Is it good to paint in Casper, WY this week?
A live 7-day go/no-go calendar for exterior paint in Casper, 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
- 20.7°F
- Overnight dew
- Low
- Rain
- 6%
- Window
- 8am–5pm
Clear to paint: temps 60–75°F, RH under 43%, surface stays 20.7°F+ above the dew point, no rain in the cure window.
- Dew margin
- 19.5°F
- Overnight dew
- Low
- Rain
- 2%
- Window
- 8am–5pm
Clear to paint: temps 57–73°F, RH under 33%, surface stays 19.5°F+ above the dew point, no rain in the cure window.
- Dew margin
- 8.5°F
- Overnight dew
- Low
- Rain
- 12%
- Window
- 8am–5pm
Clear to paint: temps 68–85°F, RH under 23%, surface stays 8.5°F+ above the dew point, no rain in the cure window.
- Dew margin
- 15.2°F
- Overnight dew
- Low
- Rain
- 5%
- Window
- 8am–5pm
Clear to paint: temps 67–85°F, RH under 36%, surface stays 15.2°F+ above the dew point, no rain in the cure window.
- Dew margin
- 12.8°F
- Overnight dew
- Low
- Rain
- 5%
- Window
- 8am–5pm
Hot afternoon (87°F, ceiling 85°F) — paint early and follow the shade.
- Dew margin
- 14.8°F
- Overnight dew
- Low
- Rain
- 5%
- Window
- 8am–5pm
Hot afternoon (90°F, ceiling 85°F) — paint early and follow the shade.
- Dew margin
- 41.1°F
- Overnight dew
- Low
- Rain
- 5%
- Window
- 8am–5pm
Hot afternoon (87°F, ceiling 85°F) — paint early and follow the shade.
- Clear to paint: temps 60–75°F, RH under 43%, surface stays 20.7°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.