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
- -1°F
- Overnight dew
- High
- Rain
- 14%
- Window
- —
High condensation risk overnight — surface dips to within -1°F of the 63°F dew point (low 62°F, 100% cloud, 4 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 2.7°F
- Overnight dew
- High
- Rain
- 7%
- Window
- —
High condensation risk overnight — surface dips to within 2.7°F of the 41°F dew point (low 42°F, 0% cloud, 3 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 8.8°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 10am–5pm
Cold mornings (down to 44°F, floor is 50°F) — wait for the surface to warm past midday before you paint.
- Dew margin
- 1.1°F
- Overnight dew
- High
- Rain
- 4%
- Window
- —
High condensation risk overnight — surface dips to within 1.1°F of the 44°F dew point (low 45°F, 0% cloud, 8 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 1.1°F
- Overnight dew
- High
- Rain
- 1%
- Window
- —
High condensation risk overnight — surface dips to within 1.1°F of the 30°F dew point (low 31°F, 1% cloud, 6 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 8.1°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 11am–5pm
Cold mornings (down to 40°F, floor is 50°F) — wait for the surface to warm past midday before you paint.
- Dew margin
- 5.7°F
- Overnight dew
- Low
- Rain
- 7%
- Window
- —
Rain likely in the 24h cure window (7% chance, ~2.4mm) — it can wash out or mar an uncured paint.
- High condensation risk overnight — surface dips to within -1°F of the 63°F dew point (low 62°F, 100% 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.