In the first half of losing weight, the body loses the most water, so the effect is also the most obvious.

After that, it should be fat and the speed will slow down.

During exercise, sweating plays the role of taking away high temperature in the body, which is a natural physiological process. When the weather is cold, you don't need to sweat to achieve this goal.

Sweating or not has nothing to do with fat loss, and the effect is the same in winter and summer.