Is it good to paint in Columbia, SC this week?
A live 7-day go/no-go calendar for exterior paint in Columbia, 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
- 6.7°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 8am–5pm
Clear to paint: temps 52–82°F, RH under 80%, surface stays 6.7°F+ above the dew point, no rain in the cure window.
- Dew margin
- 2.1°F
- Overnight dew
- High
- Rain
- 0%
- Window
- —
High condensation risk overnight — surface dips to within 2.1°F of the 47°F dew point (low 49°F, 0% cloud, 4 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- -10°F
- Overnight dew
- High
- Rain
- 0%
- Window
- —
High condensation risk overnight — surface dips to within -10°F of the 66°F dew point (low 56°F, 0% cloud, 3 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- -9.5°F
- Overnight dew
- High
- Rain
- 1%
- Window
- —
High condensation risk overnight — surface dips to within -9.5°F of the 64°F dew point (low 55°F, 0% cloud, 3 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- -2.4°F
- Overnight dew
- High
- Rain
- 3%
- Window
- —
High condensation risk overnight — surface dips to within -2.4°F of the 68°F dew point (low 65°F, 95% cloud, 2 mph wind). A fresh paint can blush/blister. Stop 4h before dew falls.
- Dew margin
- 6.4°F
- Overnight dew
- Low
- Rain
- 18%
- Window
- 9am–5pm
Clear to paint: temps 74–76°F, RH under 80%, surface stays 6.4°F+ above the dew point, no rain in the cure window.
- Dew margin
- 10°F
- Overnight dew
- Low
- Rain
- 38%
- Window
- 8am–5pm
Some rain risk (38%) during the cure window — re-check the radar before you start.
- Clear to paint: temps 52–82°F, RH under 80%, surface stays 6.7°F+ above the dew point, no rain in the cure window.
Good to go. 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.
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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.