Knowledge Explorer lesson
The Water Cycle and Weather
Where does rain come from?
Water moves around Earth again and again in the water cycle.
Evaporation: the Sun warms water in oceans, lakes, and puddles. Some of the water turns into an invisible gas called water vapor and rises into the air.
Condensation: high in the sky, the air is cooler. The water vapor cools and turns into tiny drops of water that form clouds.
Precipitation: when the drops in a cloud get big and heavy, they fall as rain, snow, sleet, or hail. Collection: the water gathers in oceans, lakes, rivers, and underground, and the cycle starts again.
Weather is what the air is like at one place and time: sunny, rainy, windy, hot, or cold. Climate is the usual weather of a place over many years. A thermometer measures temperature. Water freezes at 32°F (0°C) and, at sea level, boils at 212°F (100°C).
What you will learn
- Describe evaporation, condensation, precipitation, and collection
- Tell the difference between weather and climate
- Know the freezing and boiling points of water
Key facts
- Evaporation: liquid water warms up and becomes water vapor.
- Condensation: water vapor cools and becomes tiny drops that form clouds.
- Precipitation: water falls from clouds as rain, snow, sleet, or hail.
- Collection: water gathers in oceans, lakes, rivers, and underground.
- Weather is the conditions now. Climate is the usual weather over many years.
- Water freezes at 32°F.
- Water freezes at 0°C.
- Water boils at 212°F at sea level.