This is especially important here in Tucson-our temperature fluctuates so much (40-80 degrees), that you may be getting a tire pressure warning today!
As the weather turns colder, you may notice your tire air pressure light coming on often. This is something you need to determine is a service issue or you just to top your tires off with a little air.
Colder temperatures can affect many attributes in your vehicle. It will cause tire pressure to drop about 1 psi for every 10°F drop in air temperature. Getting a tire pressure warning light on a cold morning doesn't necessarily indicate a puncture, just that your tires are running low pressure and you need to top them off as soon as possible
If you have to keep putting air in one or more of your tires than you could have an issue with the tire(s). It is more than likely your tire's valve system. This is the mechanism that sticks out of your tire to allow you to add air. It could be corroded, broken or porous and will need to be serviced. Air loss can also be from the rim of the tire at its wheelbase. Here, air can escape, causing a slow leak.
If you continually need to add air to your tires, your best bet is to see a mechanic who can quickly fix the air issue and keep you safe on your tires. Stay safe out there!