Is it good to stain in Portland, OR this week?
A live 7-day go/no-go calendar for deck & fence stain in Portland, 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
- 5.3°F
- Overnight dew
- Low
- Rain
- 2%
- Window
- 9am–5pm
High humidity (86%, over the 85% mark) slows drying — keep an eye on the cure window.
- Dew margin
- -3.2°F
- Overnight dew
- High
- Rain
- 2%
- Window
- —
High condensation risk overnight — surface dips to within -3.2°F of the 54°F dew point (low 51°F, 100% cloud, 6 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 1.2°F
- Overnight dew
- High
- Rain
- 0%
- Window
- —
High condensation risk overnight — surface dips to within 1.2°F of the 54°F dew point (low 55°F, 0% cloud, 3 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 2.8°F
- Overnight dew
- High
- Rain
- 0%
- Window
- —
High condensation risk overnight — surface dips to within 2.8°F of the 52°F dew point (low 54°F, 5% cloud, 3 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.6°F
- Overnight dew
- High
- Rain
- 0%
- Window
- —
High condensation risk overnight — surface dips to within 0.6°F of the 54°F dew point (low 54°F, 71% cloud, 3 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 2.7°F
- Overnight dew
- High
- Rain
- 0%
- Window
- —
High condensation risk overnight — surface dips to within 2.7°F of the 52°F dew point (low 55°F, 31% cloud, 4 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 9.4°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 9am–5pm
Clear to stain: temps 55–77°F, RH under 84%, surface stays 9.4°F+ above the dew point, no rain in the cure window.
- High humidity (86%, over the 85% mark) slows drying — keep an eye on the cure window.
Caution. 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.