Symptoms
- Tire pressure warning light comes on when temperatures drop
- Tires look slightly under-inflated on a cold morning
- Pressure seems fine again once temperatures rise
Likely causes
- CommonNormal temperature-related pressure dropAir contracts in the cold, lowering PSI without any actual air loss or leak.
- CommonTire was already slightly low before the cold snapA tire near the minimum recommended pressure will dip below the warning threshold sooner in cold weather.
- PossibleActual slow leak coincidentally more noticeable in coldA real leak becomes more apparent once cold temperatures push pressure past the warning threshold.
What to do
- Check tire pressure when cold (first thing in the morning, before driving) using a gauge.
- Compare the reading to the recommended PSI on the door jamb sticker.
- Add air at a gas station or with a home compressor to bring all tires up to the recommended cold PSI.
- Recheck in a week; if pressure drops significantly again with no major temperature change, suspect a slow leak rather than just cold weather.
- Expect to top off tires a few times each winter as temperatures fluctuate; this is normal seasonal maintenance.
- Don't rely solely on the dashboard warning light timing; check manually during cold snaps.
Tools and parts
- Tire pressure gauge
- Air compressor
When to call a pro
If a specific tire needs frequent topping off well beyond what temperature alone explains, have it checked for a puncture or valve leak.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.