Earth & Space Science · free reference

Part 2: Water, Air and Weather

Water cycle, Oceans, tides and currents, Rivers, lakes, glaciers and groundwater, The atmosphere, Weather: clouds, wind, rain and storms, Climate and climate zones and Natural hazards and staying safe. Every fact lists its source, and you can share a link to any topic.

#water-cycle

In short: Water keeps moving between the ground, the air and the sea. It evaporates, condenses into clouds, falls as precipitation, and runs off or soaks in.[1]

Facts

  • The water cycle is water moving around and around, changing between liquid water, ice and water vapor.[1]
  • Any liquid water can turn into vapor, whether it is in the ocean, a puddle or even a falling raindrop.[1]
  • Water evaporates when it takes in energy, for example from the Sun or warm air.[1]

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  • Plants give off water vapor through their leaves. This is called transpiration.[1]
  • When air holds more water vapor than it can at that temperature, the vapor turns back into tiny drops. This is condensation.[1]
  • Later the water falls back down as rain, snow or another kind of precipitation.[1]
  • Water can travel across the land in streams and lakes, or as ice in glaciers.[1]
  • Some water soaks down into the soil.[1]
  • Water stored underground makes up about 30 percent of Earth's fresh water.[1]

Key words in three languages

(10)
EnglishSpanishPortuguese
water cycle[1]ciclo del agua[2]ciclo da água[3]
evaporation[1]evaporación[2]evaporação[3]
condensation[1]condensación[2]condensação[3]
precipitation[1]precipitación[2]precipitação[3]
transpiration[1]transpiración[4]transpiração[3]
runoff[1]escorrentía[2]escoamento[5]
infiltration[1]infiltración[2]infiltração[3]
groundwater[1]agua subterránea[2]água subterrânea[6]
water vapor[7]vapor de agua[2]vapor de água[3]
cloud[8]nube[2]nuvem[3]

Each word cites a page that uses it.

More practice

(3)

Members-only items are marked. The science game and the worksheets by grade are free.

Sources (8)
  1. NOAA Education · The water cycle · noaa.gov/education/resource-collections/freshwater/water-cycle (page updated Aug 25, 2026; checked Oct 26, 2026)
  2. U.S. Geological Survey · El Ciclo del Agua (General Information Product 146) · water.usgs.gov/edu/watercyclekids/download/watercycle-kids-spanish.pdf (checked Oct 26, 2026)
  3. U.S. Geological Survey, Water Science School · O Ciclo d'água (The Water Cycle, Portuguese) · usgs.gov/water-science-school/science/o-ciclo-dagua-water-cycle-portuguese (page updated Oct 4, 2019; checked Oct 26, 2026)
  4. RAE-ASALE, Diccionario de la lengua española · transpiración · dle.rae.es/transpiraci%C3%B3n (checked Oct 26, 2026)
  5. Toda Matéria (Brazilian education reference) · Ciclo da Água · todamateria.com.br/ciclo-da-agua (checked Oct 26, 2026)
  6. Serviço Geológico do Brasil (SGB) · Conheça as ações do Serviço Geológico do Brasil nas áreas de hidrologia e gestão territorial · sgb.gov.br/documents/d/guest/nova-cartilha-dht (checked Oct 26, 2026)
  7. NOAA JetStream (National Weather Service) · The Atmosphere · noaa.gov/jetstream/atmosphere (page updated Jul 2, 2024; checked Oct 26, 2026)
  8. NOAA JetStream (National Weather Service) · Ten Basic Clouds · noaa.gov/jetstream/clouds/ten-basic-clouds (page updated Mar 28, 2023; checked Oct 26, 2026)

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#oceans-tides-currents

In short: More than 70 percent of Earth is covered by ocean, which holds about 97 percent of all its water. The Moon and Sun pull up tides, and wind, temperature and saltiness drive currents.[1][2][3]

Facts

  • More than 70 percent of Earth's surface is covered by ocean.[1]
  • NASA puts the ocean's share of Earth's surface at about 71 percent.[4]
  • About 97 percent of all the water on Earth is in the ocean.[1]

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  • The pull of gravity from the Moon and the Sun causes tides.[2]
  • Tides are really very long, slow waves that travel through the ocean.[2]
  • High tide is when the top of that long wave reaches a place. Low tide is when the bottom of the wave is there.[2]
  • The difference in water height between high and low tide is the tidal range.[2]
  • An ocean current is water moving from one place to another.[3]
  • Wind pushes the currents at and near the ocean's surface.[3]
  • Differences in water temperature and saltiness also move ocean water around.[3]
  • Tides also make currents, strongest close to shore and in bays.[3]

Key words in three languages

(3)
EnglishSpanishPortuguese
ocean[1]océano[5]oceano[6]
Tide[7]Marea[8]Maré[9]
ocean current[3]corriente oceánica[10]corrente marítima[11]

Each word cites a page that uses it.

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(3)

Members-only items are marked. The science game and the worksheets by grade are free.

Sources (11)
  1. NOAA National Ocean Service · How much water is in the ocean? · oceanservice.noaa.gov/facts/oceanwater.html (page updated Sep 23, 2026; checked Oct 26, 2026)
  2. NOAA National Ocean Service · What are tides? · oceanservice.noaa.gov/facts/tides.html (page updated Sep 23, 2026; checked Oct 26, 2026)
  3. NOAA National Ocean Service · What is a current? · oceanservice.noaa.gov/facts/current.html (page updated Sep 23, 2026; checked Oct 26, 2026)
  4. NASA Science · Facts About Earth · science.nasa.gov/earth/facts (page updated Dec 5, 2025; checked Oct 26, 2026)
  5. U.S. Geological Survey · El Ciclo del Agua (General Information Product 146) · water.usgs.gov/edu/watercyclekids/download/watercycle-kids-spanish.pdf (checked Oct 26, 2026)
  6. U.S. Geological Survey, Water Science School · O Ciclo d'água (The Water Cycle, Portuguese) · usgs.gov/water-science-school/science/o-ciclo-dagua-water-cycle-portuguese (page updated Oct 4, 2019; checked Oct 26, 2026)
  7. IAU Office of Astronomy for Education (OAE) · Astronomy Translation Network glossary: English term list · astro4edu.org/resources/glossary/search (checked Oct 26, 2026)
  8. IAU Office of Astronomy for Education (OAE) · Glosario: lista de términos en español · astro4edu.org/es/resources/glossary/search (checked Oct 26, 2026)
  9. IAU Office of Astronomy for Education (OAE) · Glossário: lista de termos em português do Brasil · astro4edu.org/pt-br/resources/glossary/search (checked Oct 26, 2026)
  10. National Geographic Latinoamérica · ¿Qué son las corrientes oceánicas y por qué son importantes para el planeta? · nationalgeographicla.com/medio-ambiente/2025/03/que-son-las-corrientes-oceanicas-y-por-que-son-importantes-para-el-planeta (page updated Mar 5, 2025; checked Oct 26, 2026)
  11. Toda Matéria (Brazilian education reference) · Correntes Marítimas · todamateria.com.br/correntes-maritimas (checked Oct 26, 2026)

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#rivers-lakes-glaciers-groundwater

In short: Only a small share of Earth's water is fresh, and most of that is frozen in ice or hidden underground. Rivers and lakes hold a tiny part but supply most of the water people use.[1][2]

Facts

  • More than 96 percent of all the water on Earth is salty.[1]
  • Only about 2.5 percent of Earth's water is fresh water.[1]
  • More than 68 percent of the fresh water is frozen in ice and glaciers.[1]

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  • About another 30 percent of fresh water is underground.[1]
  • Even so, rivers and lakes supply most of the water people use each day.[1]
  • Just over 1.2 percent of fresh water is on the surface, yet it meets most of life's needs.[1]
  • Of that surface fresh water, most is ice, and about 20.9 percent is in lakes.[1]
  • Rivers hold only about 0.49 percent of surface fresh water.[1]
  • A glacier is a big build-up of ice and snow that slowly moves across the land.[2]
  • Glaciers start where snow stays all year long and piles up until it turns into ice.[2]
  • Gravity and the glacier's own great weight make it creep along like a very slow river of ice.[2]
  • The ice sheets of Antarctica and Greenland hold more than 99 percent of Earth's freshwater ice.[2]

Key words in three languages

(5)
EnglishSpanishPortuguese
groundwater[3]agua subterránea[4]água subterrânea[5]
aquifer[6]acuífero[4]aquífero[7]
glacier[2]glaciar[4]geleira[7]
river[1]río[4]rio[7]
lake[1]lago[4]lago[7]

Each word cites a page that uses it.

More practice

(9)

Members-only items are marked. The science game and the worksheets by grade are free.

Sources (7)
  1. U.S. Geological Survey, Water Science School · Where is Earth's Water? · usgs.gov/water-science-school/science/where-earths-water (page updated Jun 6, 2018; checked Oct 26, 2026)
  2. National Snow and Ice Data Center (University of Colorado Boulder) · Glaciers · nsidc.org/learn/parts-cryosphere/glaciers (checked Oct 26, 2026)
  3. NOAA Education · The water cycle · noaa.gov/education/resource-collections/freshwater/water-cycle (page updated Aug 25, 2026; checked Oct 26, 2026)
  4. U.S. Geological Survey · El Ciclo del Agua (General Information Product 146) · water.usgs.gov/edu/watercyclekids/download/watercycle-kids-spanish.pdf (checked Oct 26, 2026)
  5. Serviço Geológico do Brasil (SGB) · Conheça as ações do Serviço Geológico do Brasil nas áreas de hidrologia e gestão territorial · sgb.gov.br/documents/d/guest/nova-cartilha-dht (checked Oct 26, 2026)
  6. Soil Science Society of America, Soils 4 Kids · All About Soil · soils4kids.org/about (checked Oct 26, 2026)
  7. U.S. Geological Survey, Water Science School · O Ciclo d'água (The Water Cycle, Portuguese) · usgs.gov/water-science-school/science/o-ciclo-dagua-water-cycle-portuguese (page updated Oct 4, 2019; checked Oct 26, 2026)

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#atmosphere

In short: The atmosphere is the air around Earth, mostly nitrogen and oxygen. It has layers, and almost all weather happens in the lowest one, the troposphere.[1][2][3]

Facts

  • The atmosphere is the blanket of air around Earth, the air we breathe.[1]
  • It is made of gases with tiny bits of solid floating in it, and it reaches thousands of miles up.[1]
  • Nitrogen is by far the most common gas in dry air.[1]

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  • Near the ground, air is about 78 percent nitrogen, 21 percent oxygen and 1 percent other gases.[2]
  • Air almost always has some water vapor in it, up to about 4 percent.[1]
  • The lowest layer is the troposphere. Almost all weather happens there.[3]
  • Above it is the stratosphere, which starts 4 to 12 miles up and reaches about 31 miles.[3]
  • Higher still come the mesosphere and then the thermosphere.[3]
  • The outermost layer is the exosphere.[3]

Key words in three languages

(7)
EnglishSpanishPortuguese
water vapor[1]vapor de agua[4]vapor de água[5]
Atmosphere[6]Atmósfera[7]Atmosfera[8]
troposphere[3]troposfera[9]troposfera[10]
stratosphere[3]estratosfera[11]estratosfera[10]
mesosphere[3]mesosfera[12]mesosfera[10]
thermosphere[3]termosfera[13]termosfera[10]
exosphere[3]exosfera[14]exosfera[10]

Each word cites a page that uses it.

More practice

(6)

Members-only items are marked. The science game and the worksheets by grade are free.

Sources (14)
  1. NOAA JetStream (National Weather Service) · The Atmosphere · noaa.gov/jetstream/atmosphere (page updated Jul 2, 2024; checked Oct 26, 2026)
  2. NASA Science · Facts About Earth · science.nasa.gov/earth/facts (page updated Dec 5, 2025; checked Oct 26, 2026)
  3. NOAA JetStream (National Weather Service) · Layers of the Atmosphere · noaa.gov/jetstream/atmosphere/layers-of-atmosphere (page updated Feb 17, 2026; checked Oct 26, 2026)
  4. U.S. Geological Survey · El Ciclo del Agua (General Information Product 146) · water.usgs.gov/edu/watercyclekids/download/watercycle-kids-spanish.pdf (checked Oct 26, 2026)
  5. U.S. Geological Survey, Water Science School · O Ciclo d'água (The Water Cycle, Portuguese) · usgs.gov/water-science-school/science/o-ciclo-dagua-water-cycle-portuguese (page updated Oct 4, 2019; checked Oct 26, 2026)
  6. IAU Office of Astronomy for Education (OAE) · Astronomy Translation Network glossary: English term list · astro4edu.org/resources/glossary/search (checked Oct 26, 2026)
  7. IAU Office of Astronomy for Education (OAE) · Glosario: lista de términos en español · astro4edu.org/es/resources/glossary/search (checked Oct 26, 2026)
  8. IAU Office of Astronomy for Education (OAE) · Glossário: lista de termos em português do Brasil · astro4edu.org/pt-br/resources/glossary/search (checked Oct 26, 2026)
  9. RAE-ASALE, Diccionario de la lengua española · troposfera · dle.rae.es/troposfera (checked Oct 26, 2026)
  10. Toda Matéria (Brazilian education reference) · Camadas da atmosfera terrestre e suas características · todamateria.com.br/camadas-da-atmosfera (checked Oct 26, 2026)
  11. RAE-ASALE, Diccionario de la lengua española · estratosfera · dle.rae.es/estratosfera (checked Oct 26, 2026)
  12. RAE-ASALE, Diccionario de la lengua española · mesosfera · dle.rae.es/mesosfera (checked Oct 26, 2026)
  13. RAE-ASALE, Diccionario de la lengua española · termosfera · dle.rae.es/termosfera (checked Oct 26, 2026)
  14. RAE-ASALE, Diccionario de la lengua española · exosfera · dle.rae.es/exosfera (checked Oct 26, 2026)

See something we should correct about “The atmosphere”? Tell us.

#weather

In short: Weather includes clouds, wind, rain, snow and storms. Clouds are named by their shape and height, and strong storms include thunderstorms, tornadoes and hurricanes.[1][2][3][4]

Facts

  • Cirrus, cirrocumulus and cirrostratus are high clouds.[1]
  • Altocumulus, altostratus and nimbostratus are middle-level clouds, made mostly of water droplets.[1]
  • Cumulus, stratocumulus, stratus and cumulonimbus are low clouds made of water droplets.[1]

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  • Cumulus clouds are thick, separate clouds with sharp edges that grow upward.[1]
  • Stratus is a flat gray sheet of cloud with an even bottom.[1]
  • Cirrus clouds are thin, white wisps, often in patches or streaks.[1]
  • Cumulonimbus is the thunderstorm cloud: a thick, towering cloud shaped like a mountain.[1]
  • Nimbostratus is a dark gray cloud layer blurred by falling rain or snow.[1]
  • Wind is air moving horizontally past a place.[2]
  • Scientists estimate there can be up to 40,000 thunderstorms around the world in a single day.[5]
  • A tornado is a fast-spinning column of air that reaches from a thunderstorm cloud all the way to the ground.[3]
  • A tropical cyclone is a huge spinning system of clouds and thunderstorms that forms over warm tropical seas.[4]
  • When its steady winds reach 39 to 73 miles per hour, it is a tropical storm.[4]
  • When steady winds reach 74 miles per hour or more, it is a hurricane.[4]
  • In the Atlantic, hurricane season lasts from June 1 to November 30.[4]

Key words in three languages

(20)
EnglishSpanishPortuguese
precipitation[6]precipitación[7]precipitação[8]
weather[9]tiempo[10]tempo[11]
cloud[1]nube[7]nuvem[8]
cirrus[1]cirro[26]cirrus[27][28]
cirrocumulus[1]cirrocúmulo[26]cirrocumulus[27][28]
cirrostratus[1]cirrostrato[26]cirrostratus[27][28]
altocumulus[1]altocúmulo[26]altocumulus[27][28]
altostratus[1]altostrato[26]altostratus[27][28]
nimbostratus[1]nimbostrato[26]nimbostratus[27][28]
stratocumulus[1]estratocúmulo[26]stratocumulus[27][28]
stratus[1]estrato[26]stratus[27][28]
cumulus[1]cúmulo[26]cumulus[27][28]
cumulonimbus[1]cumulonimbo[26]cumulonimbus[27][28]
wind[13]viento[14]vento[11]
thunderstorm[1]tormenta[15]tempestade[12]
lightning[16]rayo[17]raio / relâmpago[18]
thunder[16]trueno[19]trovão[12]
tornado[3]tornado[20]tornado[12]
hurricane[4]huracán[21]furacão[22]
meteorologist[23]meteorólogo[24]meteorologista[25]

Each word cites a page that uses it.

More practice

(9)

Members-only items are marked. The science game and the worksheets by grade are free.

Sources (28)
  1. NOAA JetStream (National Weather Service) · Ten Basic Clouds · noaa.gov/jetstream/clouds/ten-basic-clouds (page updated Mar 28, 2023; checked Oct 26, 2026)
  2. NOAA National Weather Service · Glossary: Wind · forecast.weather.gov/glossary.php?word=wind (checked Oct 26, 2026)
  3. NOAA National Weather Service · Tornado Safety · weather.gov/safety/tornado (page updated Jul 9, 2024; checked Oct 26, 2026)
  4. NOAA National Hurricane Center · Tropical Cyclone Climatology · nhc.noaa.gov/climo (checked Oct 26, 2026)
  5. NOAA JetStream (National Weather Service) · Thunderstorms · noaa.gov/jetstream/thunderstorms (page updated Apr 14, 2023; checked Oct 26, 2026)
  6. NOAA Education · The water cycle · noaa.gov/education/resource-collections/freshwater/water-cycle (page updated Aug 25, 2026; checked Oct 26, 2026)
  7. U.S. Geological Survey · El Ciclo del Agua (General Information Product 146) · water.usgs.gov/edu/watercyclekids/download/watercycle-kids-spanish.pdf (checked Oct 26, 2026)
  8. U.S. Geological Survey, Water Science School · O Ciclo d'água (The Water Cycle, Portuguese) · usgs.gov/water-science-school/science/o-ciclo-dagua-water-cycle-portuguese (page updated Oct 4, 2019; checked Oct 26, 2026)
  9. NOAA JetStream (National Weather Service) · Layers of the Atmosphere · noaa.gov/jetstream/atmosphere/layers-of-atmosphere (page updated Feb 17, 2026; checked Oct 26, 2026)
  10. RAE-ASALE, Diccionario de la lengua española · tiempo · dle.rae.es/tiempo (checked Oct 26, 2026)
  11. Toda Matéria (Brazilian education reference) · Diferença entre Clima e Tempo · todamateria.com.br/diferenca-entre-tempo-e-clima (checked Oct 26, 2026)
  12. Toda Matéria (Brazilian education reference) · Todos os tipos de nuvens explicados · todamateria.com.br/tipos-de-nuvens (checked Oct 26, 2026)
  13. NOAA National Ocean Service · What is a current? · oceanservice.noaa.gov/facts/current.html (page updated Sep 23, 2026; checked Oct 26, 2026)
  14. RAE-ASALE, Diccionario de la lengua española · viento · dle.rae.es/viento (checked Oct 26, 2026)
  15. RAE-ASALE, Diccionario de la lengua española · tormenta · dle.rae.es/tormenta (checked Oct 26, 2026)
  16. NOAA National Weather Service · Overview: Lightning Safety · weather.gov/safety/lightning-safety-overview (page updated Jul 11, 2024; checked Oct 26, 2026)
  17. RAE-ASALE, Diccionario de la lengua española · rayo · dle.rae.es/rayo (checked Oct 26, 2026)
  18. Dicionário Priberam da Língua Portuguesa · relâmpago · dicionario.priberam.org/rel%C3%A2mpago (checked Oct 26, 2026)
  19. RAE-ASALE, Diccionario de la lengua española · trueno · dle.rae.es/trueno (checked Oct 26, 2026)
  20. RAE-ASALE, Diccionario de la lengua española · tornado · dle.rae.es/tornado (checked Oct 26, 2026)
  21. RAE-ASALE, Diccionario de la lengua española · huracán · dle.rae.es/hurac%C3%A1n (checked Oct 26, 2026)
  22. Dicionário Priberam da Língua Portuguesa · furacão · dicionario.priberam.org/furac%C3%A3o (checked Oct 26, 2026)
  23. U.S. Bureau of Labor Statistics, Occupational Outlook Handbook · Atmospheric Scientists, Including Meteorologists · bls.gov/ooh/life-physical-and-social-science/atmospheric-scientists-including-meteorologists.htm (page updated Aug 27, 2026; checked Oct 26, 2026)
  24. RAE-ASALE, Diccionario de la lengua española · meteorólogo · dle.rae.es/meteor%C3%B3logo (checked Oct 26, 2026)
  25. Dicionário Priberam da Língua Portuguesa · meteorologista · dicionario.priberam.org/meteorologista (checked Oct 26, 2026)
  26. Organización Meteorológica Mundial (OMM), ETRP · Identificación y observación de nubes para traductores e intérpretes de la OMM · etrp.wmo.int/pluginfile.php/57467/mod_resource/content/1/Bl2Tema4.pdf (checked Oct 30, 2026)
  27. Instituto Nacional de Meteorologia (INMET) · Glossário · portal.inmet.gov.br/glossario/glossario (checked Oct 30, 2026)
  28. World Meteorological Organization, International Cloud Atlas · Genera · cloudatlas.wmo.int/en/clouds-genera.html (checked Oct 30, 2026)

See something we should correct about “Weather: clouds, wind, rain and storms”? Tell us.

#climate-and-climate-zones

In short: Climate is the usual weather of a place over many years. Scientists sort climates into groups such as tropical, dry and polar, and latitude and height above sea level both shape them.[1][7]

Facts

  • Climate means the usual weather of a place averaged over a long time, usually 30 years or more.[1]
  • Climate change is a long-lasting shift in a place's usual weather patterns.[1]
  • Global warming is the slow, long-term heating of Earth's surface measured since before factories became common.[1]

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  • NASA says the main driver is burning fossil fuels, which adds heat-trapping gases to the air.[1]
  • A well-known way to sort climates comes from the scientist Wladimir Köppen, who lived from 1846 to 1940. He grouped climates mostly by temperature and latitude.[7]
  • NOAA lists six main groups: tropical, dry, moist subtropical, moist continental, polar and highland.[7]
  • In tropical climates, every month has an average temperature above 64 °F (18 °C), and a lot of rain falls each year.[7]
  • Polar climates are cold all year. Even the warmest month averages less than 50 °F (10 °C).[7]
  • Moist subtropical climates have warm, humid summers and mild winters. Moist continental climates have warm to cool summers and cold winters.[7]
  • In dry climates, more water could dry up into the air each year than falls as rain or snow.[7]
  • How far a place is from the equator (its latitude) matters a lot for its climate.[7]
  • Height matters too. In the mountains, climate can change quickly over short distances as the land rises.[7]
  • NASA reports that Earth's air now has about 430 parts of carbon dioxide in every million parts of air.[2]
  • Average sea level around the world has gone up about 4 inches since January 1993.[2]

Key words in three languages

(2)
EnglishSpanishPortuguese
climate[1]clima[3]clima[4]
global warming[1]Calentamiento global[5]Aquecimento global[6]

Each word cites a page that uses it.

More practice

(6)

Members-only items are marked. The science game and the worksheets by grade are free.

Sources (7)
  1. NASA Science · What Is Climate Change? · science.nasa.gov/climate-change/what-is-climate-change (page updated Oct 21, 2024; checked Oct 26, 2026)
  2. NASA Science (Kids) · Earth · science.nasa.gov/kids/earth (page updated Sep 26, 2025; checked Oct 26, 2026)
  3. RAE-ASALE, Diccionario de la lengua española · clima · dle.rae.es/clima (checked Oct 26, 2026)
  4. Toda Matéria (Brazilian education reference) · Diferença entre Clima e Tempo · todamateria.com.br/diferenca-entre-tempo-e-clima (checked Oct 26, 2026)
  5. IAU Office of Astronomy for Education (OAE) · Glosario: lista de términos en español · astro4edu.org/es/resources/glossary/search (checked Oct 26, 2026)
  6. IAU Office of Astronomy for Education (OAE) · Glossário: lista de termos em português do Brasil · astro4edu.org/pt-br/resources/glossary/search (checked Oct 26, 2026)
  7. NOAA JetStream (National Weather Service) · Climate Zones · noaa.gov/jetstream/global/climate-zones (page updated Jun 13, 2023; checked Oct 30, 2026)

See something we should correct about “Climate and climate zones”? Tell us.

#natural-hazards

In short: Knowing what to do keeps families safe: go indoors when thunder roars, shelter in an inside room during a tornado warning, never go into flood water, and Drop, Cover, Hold On in an earthquake.[1][2][3][4]

Facts

  • Every member of the family can help get ready. Make a family emergency plan together before a disaster happens.[21]
  • A tornado WATCH means tornadoes could form in the area. Go over your family plan and check your safe place.[2]
  • A tornado WARNING means a tornado has been seen or shows up on radar. Go to an inside room on the lowest floor of a strong building, away from windows.[2]

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  • At home during a tornado warning, go to the basement, a safe room, or an inside room with no windows.[5]
  • If you can hear thunder, it is time to go inside.[1]
  • Nowhere outdoors is safe while a thunderstorm is nearby.[1]
  • Strong buildings and cars or trucks with hard roofs are safe places.[1]
  • Wait 30 minutes after the last thunder or lightning before going back out.[1]
  • Never walk, swim or ride through flood water. Turn around instead.[3]
  • Moving water only six inches deep can knock a person over, and one foot of it can carry away a car.[3]
  • Storm surge is ocean water pushed up onto land by a storm's winds. In the United States it has been the most dangerous part of hurricanes.[6]
  • Hurricane winds can turn loose things left outside into flying objects, so they should be brought in.[6]
  • For earthquakes, remember: Drop, Cover, Hold On.[4]
  • Most lava flows are slow enough for people to move away from them.[7]

Key words in three languages

(6)
EnglishSpanishPortuguese
thunderstorm[8]tormenta[9]tempestade[10]
lightning[1]rayo[11]raio / relâmpago[12]
thunder[1]trueno[13]trovão[10]
tornado[14]tornado[15]tornado[10]
hurricane[16]huracán[17]furacão[18]
flood[3]inundación[19]inundação[20]

Each word cites a page that uses it.

More practice

(3)

Members-only items are marked. The science game and the worksheets by grade are free.

Sources (21)
  1. NOAA National Weather Service · Overview: Lightning Safety · weather.gov/safety/lightning-safety-overview (page updated Jul 11, 2024; checked Oct 26, 2026)
  2. NOAA National Weather Service · Understand Tornado Alerts · weather.gov/safety/tornado-ww (page updated May 14, 2024; checked Oct 26, 2026)
  3. FEMA, Ready.gov · Floods · ready.gov/floods (page updated Oct 17, 2024; checked Oct 26, 2026)
  4. FEMA, Ready.gov · Earthquakes · ready.gov/earthquakes (checked Oct 26, 2026)
  5. NOAA National Weather Service · What to do During a Tornado · weather.gov/safety/tornado-during (page updated Jun 14, 2019; checked Oct 26, 2026)
  6. NOAA National Weather Service · Hurricane Safety Tips and Resources · weather.gov/safety/hurricane (page updated Jun 12, 2025; checked Oct 26, 2026)
  7. U.S. Geological Survey, Volcano Hazards Program · Lava flows destroy everything in their path · usgs.gov/programs/VHP/lava-flows-destroy-everything-their-path (checked Oct 26, 2026)
  8. NOAA JetStream (National Weather Service) · Ten Basic Clouds · noaa.gov/jetstream/clouds/ten-basic-clouds (page updated Mar 28, 2023; checked Oct 26, 2026)
  9. RAE-ASALE, Diccionario de la lengua española · tormenta · dle.rae.es/tormenta (checked Oct 26, 2026)
  10. Toda Matéria (Brazilian education reference) · Todos os tipos de nuvens explicados · todamateria.com.br/tipos-de-nuvens (checked Oct 26, 2026)
  11. RAE-ASALE, Diccionario de la lengua española · rayo · dle.rae.es/rayo (checked Oct 26, 2026)
  12. Dicionário Priberam da Língua Portuguesa · relâmpago · dicionario.priberam.org/rel%C3%A2mpago (checked Oct 26, 2026)
  13. RAE-ASALE, Diccionario de la lengua española · trueno · dle.rae.es/trueno (checked Oct 26, 2026)
  14. NOAA National Weather Service · Tornado Safety · weather.gov/safety/tornado (page updated Jul 9, 2024; checked Oct 26, 2026)
  15. RAE-ASALE, Diccionario de la lengua española · tornado · dle.rae.es/tornado (checked Oct 26, 2026)
  16. NOAA National Hurricane Center · Tropical Cyclone Climatology · nhc.noaa.gov/climo (checked Oct 26, 2026)
  17. RAE-ASALE, Diccionario de la lengua española · huracán · dle.rae.es/hurac%C3%A1n (checked Oct 26, 2026)
  18. Dicionário Priberam da Língua Portuguesa · furacão · dicionario.priberam.org/furac%C3%A3o (checked Oct 26, 2026)
  19. RAE-ASALE, Diccionario de la lengua española · inundación · dle.rae.es/inundaci%C3%B3n (checked Oct 26, 2026)
  20. Dicionário Priberam da Língua Portuguesa · inundação · dicionario.priberam.org/inunda%C3%A7%C3%A3o (checked Oct 26, 2026)
  21. FEMA, Ready.gov · Ready Kids · ready.gov/kids (checked Oct 30, 2026)

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Free printables for this part

Printables that go with the topics on this page.

Printables with a black and white button also come in a low-ink version, good for coloring and filling in.

  • The water cycle

    Free PDFGrades 3–6

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  • Cloud identification chart

    Free PDFGrades 3–6

    Color