Is it good to stain in Harrisburg, PA this week?
A live 7-day go/no-go calendar for deck & fence stain in Harrisburg, 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
- 3.3°F
- Overnight dew
- High
- Rain
- 2%
- Window
- —
High condensation risk overnight — surface dips to within 3.3°F of the 67°F dew point (low 69°F, 15% cloud, 3 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 6.5°F
- Overnight dew
- Low
- Rain
- 5%
- Window
- 8am–5pm
Clear to stain: temps 72–87°F, RH under 82%, surface stays 6.5°F+ above the dew point, no rain in the cure window.
- Dew margin
- 0.9°F
- Overnight dew
- High
- Rain
- 25%
- Window
- —
High condensation risk overnight — surface dips to within 0.9°F of the 69°F dew point (low 69°F, 100% cloud, 10 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 1.2°F
- Overnight dew
- High
- Rain
- 79%
- Window
- —
High condensation risk overnight — surface dips to within 1.2°F of the 73°F dew point (low 71°F, 7% cloud, 4 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 4.8°F
- Overnight dew
- High
- Rain
- 19%
- Window
- —
High condensation risk overnight — surface dips to within 4.8°F of the 54°F dew point (low 59°F, 0% cloud, 3 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 6.7°F
- Overnight dew
- Low
- Rain
- 4%
- Window
- 8am–5pm
Clear to stain: temps 64–85°F, RH under 71%, surface stays 6.7°F+ above the dew point, no rain in the cure window.
- Dew margin
- 13.8°F
- Overnight dew
- Low
- Rain
- 12%
- Window
- 8am–5pm
Clear to stain: temps 71–90°F, RH under 72%, surface stays 13.8°F+ above the dew point, no rain in the cure window.
- High condensation risk overnight — surface dips to within 3.3°F of the 67°F dew point (low 69°F, 15% cloud, 3 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
Hold off. These are forecast numbers — confirm the surface temperature on-site before you start.
Why these thresholds
Stain applied to a damp or dew-wet board can't penetrate — it beads, stays tacky and flakes. Wood must be dry and stay above the dew point while it sets.
- • Surface temp must stay 5°F above the dew point through application and cure (ASTM D3276 / ISO 8502-42).
- • Air + surface in the 50–90°F band (low-temp lines to 45°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.