As the weather turns colder, sitting in the hot tub becomes more appealing. Your can use your hot tub real-round in most climates, as long as you follow proper maintenance.
In colder weather, the main concern is keeping the hot tub warm. You don't want the pipes or any part of the hot tub to freeze. A freeze protection system or putting your hot tub in auto-heat mode should keep it safe.
Also, make sure you have enough water in the hot tub to keep it from freezing.
The air jets are inserting colder air into the water. In the colder months, this just means it will take more energy to keep your hot tub warm. To keep your energy bills under control, try to use the air jets sparingly when it's really cold out.