Why do we get much lower scores in long jump or pull-ups than usual when it rains or when the weather is cloudy?

When I was in the third year of junior high school, the weather was still very cold. The physical education teacher gave us a great training intensity of 1. He said that the greater the intensity of your training now, the easier it will be for you to run in hot weather. Because the outside temperature is too low, some nerves are slow to respond, so you can do some warm-up exercises before exercise.