Is it good to paint in Rochester, MN this week?
A live 7-day go/no-go calendar for exterior paint in Rochester, 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
- 4.7°F
- Overnight dew
- Watch
- Rain
- 18%
- Window
- —
Humidity peaks at 97% — well above the 85% ceiling; cure stalls and moisture gets trapped.
- Dew margin
- 1.2°F
- Overnight dew
- High
- Rain
- 36%
- Window
- —
High condensation risk overnight — surface dips to within 1.2°F of the 65°F dew point (low 63°F, 100% cloud, 4 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- -1.9°F
- Overnight dew
- High
- Rain
- 27%
- Window
- —
High condensation risk overnight — surface dips to within -1.9°F of the 71°F dew point (low 68°F, 100% cloud, 16 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.8°F
- Overnight dew
- High
- Rain
- 45%
- Window
- —
High condensation risk overnight — surface dips to within 0.8°F of the 66°F dew point (low 61°F, 11% cloud, 7 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 7.6°F
- Overnight dew
- Low
- Rain
- 11%
- Window
- 10am–5pm
High humidity (93%, over the 85% mark) slows drying — keep an eye on the cure window.
- Dew margin
- -0.8°F
- Overnight dew
- High
- Rain
- 5%
- Window
- —
High condensation risk overnight — surface dips to within -0.8°F of the 62°F dew point (low 61°F, 100% cloud, 9 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.1°F
- Overnight dew
- High
- Rain
- 26%
- Window
- —
High condensation risk overnight — surface dips to within 0.1°F of the 69°F dew point (low 69°F, 81% cloud, 6 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.
- Watch overnight dew — surface comes within 4.7°F of the dew point (margin is 5°F). Time the coat to dry well before evening.
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.