* Clouds can act as a blanket. During the day, clouds can reflect sunlight back into space, making it cooler on the ground. Think of a white T-shirt on a hot day - it keeps you cooler than a dark shirt because it reflects more sunlight.
* Clouds can also trap heat. At night, clouds can act like a blanket and prevent heat from escaping into space. This can make it warmer at night than it would be on a clear night.
So, it depends!
* During the day: Clouds can make it cooler.
* At night: Clouds can make it warmer.
It also depends on the type of cloud:
* Thick, low clouds like stratus clouds are more likely to block sunlight during the day and trap heat at night.
* High, thin clouds like cirrus clouds have less of an impact on temperature.
Ultimately, it's a combination of factors that determine how clouds affect temperature.
