Humidity Guidelines
Under 50% → Ideal
55–60% → Use caution (small repairs only)
Above 60% → Not recommended
If humidity is consistently above 60%, wait for better conditions or paint in a controlled indoor space.
Why Humidity Matters
High humidity slows solvent evaporation and curing.
This can lead to:
longer dry times
soft or unstable paint
poor adhesion
dull or uneven finish
Waiting longer between coats does not fully correct poor conditions.
In some cases, paint may feel dry on the surface but remain soft underneath.
How to Check Humidity
Ask your phone or smart speaker:
“What’s the humidity right now?”Check your weather app
Search: “humidity near me”
If You Must Paint (55–60%)
Apply thin, even coats only
Allow extra time between coats
Use a test card to confirm dry time
Do not use heat to speed up drying.
Heat (hairdryers, heat guns) can negatively affect the finish.
For waterborne aerosol paint, gentle airflow only (no heat) may help (e.g., a fan or hairdryer on cool setting, at a distance).
For solventborne aerosol paint, do not use a hairdryer—allow it to dry naturally.
WHAT NOT TO DO
Do not paint above 60% humidity
Do not apply heavy coats
Do not use heat to dry
After Painting (Keep It Dry)
Keep the repair dry while the clear coat cures:
Small repairs: can drive after a few hours if it stays dry
If rain is possible: wait at least 24 hours
Larger or sprayed repairs: wait 48 hours before exposure to rain or snow
When to Wait to Repair
Wait for better conditions if:
Humidity is above 60%
You cannot keep the surface dry
The repair is large or highly visible
Important: While additional drying time can help, high humidity (above ~60% RH) can still affect results. In persistently humid conditions, it’s best to wait for better conditions or move to a more controlled environment.
FAQ
Can I paint my car in humid climates like Seattle?
Yes—but timing matters. Look for lower-humidity windows or paint indoors in a controlled space.
Will a fan or airflow help drying?
Airflow does not significantly improve drying or overcome humidity. It is not a substitute for proper conditions.
You may use gentle airflow (no heat) to help drying in some cases.
Do not apply heat directly to the paint.
For solventborne paint, allow it to dry naturally without forced air.
Why is my paint still soft or slow to dry?
Humidity may be too high, which slows solvent evaporation and curing.
Additional time can help, but results may still be affected if conditions are not ideal.Heavy coats can also cause this.
If paint is applied too thick, the surface may dry while the layer underneath stays soft and slow to cure.