Why Does the Wind Blow Uphill During the Day and Downhill at Night?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why does the wind blow uphill during the day and downhill at night?

The Big Idea

Mountain winds switch directions between day and night! In the day, the wind often blows uphill. At night, it flows downhill.

Daytime Heat

Step one: the Sun warms the slopes. In the daytime, the Sun heats the slopes, which warm the air touching them. Warm air is lighter than cold air, so it floats upward, like a bubble in water.

Uphill Breeze

Step two: air drifts uphill. Warm air rises and drifts uphill, along the slope. Mountain winds often feel gentle in the day. Hawks and glider pilots use these daytime updrafts to rise.

Night Chill

Step three: night slides down. At night, the slopes cool quickly, and the cooled air gets heavy and slides downhill. These are called valley and mountain breezes. They happen on many clear days, if the big weather is calm.

A Closer Look

Let's take a closer look! By day, the Sun warms the slopes. The warm air rises uphill. At night, the slopes cool off. And the cold, heavy air slides downhill.

Quick Facts

Quick facts! Mountain breezes at night can feel cold on a valley floor. Cold air is heavy, so it flows down like invisible water. Daytime updrafts help birds and glider planes climb. Campers in valleys need warm layers at night.

Think Like a Scientist

Now, think like a scientist! On a sunny day, blow bubbles over sunny pavement. Then blow bubbles over shady grass. Which way do they drift? Watch carefully. Warm air rises, so bubbles may lift over warm ground.

Outro

Warm air rises by day, and cold air slides down by night. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!