This might be a little surprising, but solar generation doesn;t have much to do with how hot the weather is. Yes, summer days when it’s not cloudy are a great time to see solar kick in strongly,. but extreme heat is not good for generation as well.

This is because solar panels generate electricity thanks to the flow of electrons that are stimulated by light falling on the cell. Most panels available today are tested for optimum operations between 15 to 35 or even 40 degrees centigrade.

When temperatures spike, these electrons can bounce around too much and too fast, reducing voltage, or the amount of electricity generated.

Thus, for every rise in temperature beyond 38 degrees or so, efficiency can come down by 0.5%. At 45 degrees, you could be looking at a 3-4% drop in efficiency therefore.
Excessive heat can even lead to malfunctions of other parts in the system.