Is it good to paint in Naperville, IL this week?
A live 7-day go/no-go calendar for exterior paint in Naperville, built from the local forecast against the 5°F-above-dew-point rule. We lead with the signal a weather app misses: overnight condensation risk.
- Dew margin
- -0.5°F
- Overnight dew
- High
- Rain
- 11%
- Window
- —
High condensation risk overnight — surface dips to within -0.5°F of the 74°F dew point (low 73°F, 4% cloud, 10 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 1.8°F
- Overnight dew
- High
- Rain
- 3%
- Window
- —
High condensation risk overnight — surface dips to within 1.8°F of the 72°F dew point (low 74°F, 48% cloud, 9 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 1.8°F
- Overnight dew
- High
- Rain
- 1%
- Window
- —
High condensation risk overnight — surface dips to within 1.8°F of the 75°F dew point (low 73°F, 0% cloud, 8 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 2°F
- Overnight dew
- High
- Rain
- 2%
- Window
- —
High condensation risk overnight — surface dips to within 2°F of the 76°F dew point (low 75°F, 0% cloud, 8 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 3.8°F
- Overnight dew
- Watch
- Rain
- 26%
- Window
- —
Too hot — high of 93°F is well over the 85°F ceiling; the film skins over before it can level or adhere.
- Dew margin
- 0.4°F
- Overnight dew
- High
- Rain
- 20%
- Window
- —
High condensation risk overnight — surface dips to within 0.4°F of the 73°F dew point (low 73°F, 57% cloud, 6 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- -1.1°F
- Overnight dew
- High
- Rain
- 19%
- Window
- —
High condensation risk overnight — surface dips to within -1.1°F of the 76°F dew point (low 75°F, 36% cloud, 7 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- High condensation risk overnight — surface dips to within -0.5°F of the 74°F dew point (low 73°F, 4% cloud, 10 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Hot afternoon (87°F, ceiling 85°F) — paint early and follow the shade.
Hold off. These are forecast numbers — confirm the surface temperature on-site before you start.
Why these thresholds
Overnight dew condensing on a fresh coat causes blistering, surfactant leaching and peeling — the cause of 40%+ of exterior paint failures.
- • Surface temp must stay 5°F above the dew point through application and cure (ASTM D3276 / ISO 8502-42).
- • Air + surface in the 50–85°F band (low-temp lines to 35°F).
- • Humidity under 85%; ideally under 70%.
- • No rain for 24h after application.
- • We use the forecast ground-surface temperature as a surface-temp proxy — confirm on-site with an IR thermometer.
Free in the beta
Watch this job site 24/7
Get an email the moment overnight dew, rain, or an out-of-range stretch threatens a fresh coat — and a morning digest with the best window ahead. No app to check; we watch the forecast for you.