Is it good to paint in Manchester, NH this week?
A live 7-day go/no-go calendar for exterior paint in Manchester, 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
- -0.2°F
- Overnight dew
- High
- Rain
- 5%
- Window
- —
High condensation risk overnight — surface dips to within -0.2°F of the 59°F dew point (low 58°F, 8% cloud, 5 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.3°F
- Overnight dew
- High
- Rain
- 1%
- Window
- —
High condensation risk overnight — surface dips to within 0.3°F of the 58°F dew point (low 58°F, 0% cloud, 4 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.6°F
- Overnight dew
- High
- Rain
- 61%
- Window
- —
High condensation risk overnight — surface dips to within 0.6°F of the 66°F dew point (low 66°F, 100% cloud, 4 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.6°F
- Overnight dew
- High
- Rain
- 23%
- Window
- —
High condensation risk overnight — surface dips to within 0.6°F of the 66°F dew point (low 65°F, 27% cloud, 1 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.3°F
- Overnight dew
- High
- Rain
- 7%
- Window
- —
High condensation risk overnight — surface dips to within 0.3°F of the 68°F dew point (low 68°F, 32% cloud, 2 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 2.2°F
- Overnight dew
- Watch
- Rain
- 29%
- Window
- —
Too hot — high of 102°F is well over the 85°F ceiling; the film skins over before it can level or adhere.
- Dew margin
- 0°F
- Overnight dew
- High
- Rain
- 43%
- Window
- —
High condensation risk overnight — surface dips to within 0°F of the 71°F dew point (low 70°F, 64% cloud, 5 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- High condensation risk overnight — surface dips to within -0.2°F of the 59°F dew point (low 58°F, 8% cloud, 5 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Humidity peaks at 99% — 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.