The temperature changes throughout the day due to the Earth’s rotation and the effects of the sun’s radiation.

Here’s a more detailed explanation:

Diurnal temperature variation:

During the day, the sun heats the Earth’s surface through solar radiation. The surface absorbs this heat, causing the air temperature to rise.

At night, the Earth’s surface cools through infrared radiation, as it emits the heat it absorbed during the day. This causes the air temperature to drop.

Uneven heating of the Earth’s surface:

The Earth’s surface is made up of different materials (land, water, vegetation, etc.) that have varying abilities to absorb and emit heat.

Land heats up and cools down faster than water, leading to greater temperature fluctuations over land compared to water bodies.

Areas with more vegetation or cloud cover tend to have smaller temperature variations, as the vegetation and clouds can absorb and reflect some of the solar radiation.

Angle of the sun’s rays:

The angle at which the sun’s rays hit the Earth’s surface changes throughout the day, with the sun being highest in the sky around noon.

When the sun’s rays are more direct (i.e., at midday), the surface receives more concentrated solar radiation, leading to higher temperatures.

In the early morning and late afternoon, the sun’s rays are more oblique, spreading the radiation over a larger area and resulting in lower temperatures.

Atmospheric effects:

The atmosphere also plays a role in temperature changes, as it can absorb, reflect, and re-radiate heat.

Clouds, humidity, and wind can all impact the rate of heating and cooling at the surface.

The combination of these factors leads to the characteristic daily temperature fluctuations that we observe, with the highest temperatures typically occurring in the late afternoon and the lowest temperatures just before sunrise.