Is it good to paint in Ann Arbor, MI this week?
A live 7-day go/no-go calendar for exterior paint in Ann Arbor, 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
- -0.3°F
- Overnight dew
- High
- Rain
- 0%
- Window
- —
High condensation risk overnight — surface dips to within -0.3°F of the 46°F dew point (low 45°F, 7% cloud, 4 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- -1°F
- Overnight dew
- High
- Rain
- 1%
- Window
- —
High condensation risk overnight — surface dips to within -1°F of the 51°F dew point (low 50°F, 100% cloud, 7 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 7.9°F
- Overnight dew
- Low
- Rain
- 22%
- Window
- 9am–5pm
High humidity (86%, over the 85% mark) slows drying — keep an eye on the cure window.
- Dew margin
- -0.2°F
- Overnight dew
- High
- Rain
- 62%
- Window
- —
High condensation risk overnight — surface dips to within -0.2°F of the 66°F dew point (low 50°F, 100% cloud, 7 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- -1.4°F
- Overnight dew
- High
- Rain
- 62%
- Window
- —
High condensation risk overnight — surface dips to within -1.4°F of the 41°F dew point (low 38°F, 9% cloud, 8 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- -13.3°F
- Overnight dew
- High
- Rain
- 22%
- Window
- —
High condensation risk overnight — surface dips to within -13.3°F of the 53°F dew point (low 40°F, 100% cloud, 9 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 5.9°F
- Overnight dew
- Low
- Rain
- 20%
- Window
- 11am–5pm
High humidity (88%, over the 85% mark) slows drying — keep an eye on the cure window.
- High condensation risk overnight — surface dips to within -0.3°F of the 46°F dew point (low 45°F, 7% cloud, 4 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Humidity peaks at 97% — well above the 85% ceiling; cure stalls and moisture gets trapped.
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.