Is it hot or cold? Windy or still? Sunny, cloudy, rainy or snowy? That is the weather: what the air is like at a place right now.
Key idea
Weather is measured with tools: a thermometer (temperature), a rain gauge (how much rain fell), a wind vane (which way the wind blows from), an anemometer (wind speed) and a barometer (air pressure).
Climate is different from weather. Climate is the usual weather of a place over many years: a desert has a dry climate even if it rains one day.
| Clouds | What they often mean |
|---|---|
| Puffy white cumulus | fair weather |
| Tall, dark cumulonimbus | thunderstorms |
| Thin, wispy cirrus, high up | fair now; a change may be coming |
| Flat gray stratus sheets | gray skies, drizzle |
Worked example: Weather or climate?
"It snowed in our town last Tuesday." Weather or climate?
- It tells about one day.
Answer: Weather.
Common mistake
A wind vane points to where the wind comes from. A "north wind" blows from the north toward the south.
Try it at home
- Keep a weather journal for two weeks: the temperature, the clouds, the wind and any rain or snow each day.
- Make a rain gauge: a straight-sided jar outside, away from trees. Measure the water with a ruler after it rains, then empty it.
Going further. Weather and Climate in Earth Science, and the Weather and Climate course for teens.