Is it good to paint in Germantown, MD this week?
A live 7-day go/no-go calendar for exterior paint in Germantown, 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
- -0.8°F
- Overnight dew
- High
- Rain
- 16%
- Window
- —
High condensation risk overnight — surface dips to within -0.8°F of the 67°F dew point (low 67°F, 14% cloud, 2 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 1.7°F
- Overnight dew
- High
- Rain
- 11%
- Window
- —
High condensation risk overnight — surface dips to within 1.7°F of the 65°F dew point (low 67°F, 27% cloud, 3 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 3.7°F
- Overnight dew
- High
- Rain
- 3%
- Window
- —
High condensation risk overnight — surface dips to within 3.7°F of the 66°F dew point (low 70°F, 33% cloud, 6 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 4.4°F
- Overnight dew
- High
- Rain
- 3%
- Window
- —
High condensation risk overnight — surface dips to within 4.4°F of the 69°F dew point (low 73°F, 0% cloud, 3 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 5.8°F
- Overnight dew
- Low
- Rain
- 3%
- Window
- —
Too hot — high of 98°F is well over the 85°F ceiling; the film skins over before it can level or adhere.
- Dew margin
- 9.3°F
- Overnight dew
- Low
- Rain
- 19%
- Window
- —
Too hot — high of 100°F is well over the 85°F ceiling; the film skins over before it can level or adhere.
- Dew margin
- 1.5°F
- Overnight dew
- High
- Rain
- 38%
- Window
- —
High condensation risk overnight — surface dips to within 1.5°F of the 70°F dew point (low 72°F, 100% cloud, 6 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- High condensation risk overnight — surface dips to within -0.8°F of the 67°F dew point (low 67°F, 14% cloud, 2 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.