Many experience itching on their legs whenever they go out to run, regardless of weather and regardless of what they’re wearing. Why?
Well, nothing’s biting you and you don’t have some sort of skin condition. So over the counter remedies aren’t going to do you much good.
The reason your legs itch is because when you start running, you activate previously dormant nerves in your legs. The sudden stimulus compels your legs to send the sensation of itching up your nerve fibers back to your brain.
So your legs itch, and the temptation is to think that something’s happening on your skin. But the reality is that your legs are basically waking up and using more energy. Often, if you continue running through it, the sensation passes.