Symptoms
- Light comes on with the first cold morning of the season
- All tires may be slightly low rather than just one
- Light may turn off later in the day as tires warm up
Likely causes
- CommonSeasonal temperature drop lowering tire pressureCold air is denser, so pressure inside the tire drops as temperatures fall.
- CommonTires were already slightly low before the temperature droppedA borderline pressure can tip into warning range once it's colder.
- PossibleActual slow leak coincidentally noticed in cold weatherWorth ruling out if the pressure doesn't recover with adding air.
What to do
- Check all four tire pressures with a gauge on a cold morning, before driving.
- Compare readings to the number on the door jamb sticker, not the tire sidewall.
- Add air to each tire that's below the recommended pressure.
- Recheck in a week or two, since pressure will keep dropping through the season as it gets colder.
- If a tire consistently loses more pressure than the others, check it for a nail or slow leak.
- Consider checking tire pressure monthly through the winter, since it changes with each cold snap.
Tools and parts
- Tire pressure gauge
- Air compressor or access to a gas station air pump
When to call a pro
See a tire shop if one tire consistently loses more air than the others, which points to a leak rather than just cold weather.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.