Is it good to stain in St. Paul, MN this week?
A live 7-day go/no-go calendar for deck & fence stain in St. Paul, 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
- 4.2°F
- Overnight dew
- High
- Rain
- 0%
- Window
- —
High condensation risk overnight — surface dips to within 4.2°F of the 40°F dew point (low 42°F, 0% cloud, 3 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 6.2°F
- Overnight dew
- Low
- Rain
- 7%
- Window
- 10am–5pm
Cold mornings (down to 43°F, floor is 50°F) — wait for the surface to warm past midday before you stain.
- Dew margin
- 3.2°F
- Overnight dew
- Watch
- Rain
- 29%
- Window
- 9am–5pm
Watch overnight dew — surface comes within 3.2°F of the dew point (margin is 5°F). Time the coat to dry well before evening.
- Dew margin
- 10.7°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 9am–5pm
Clear to stain: temps 53–67°F, RH under 76%, surface stays 10.7°F+ above the dew point, no rain in the cure window.
- Dew margin
- 8.4°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 9am–5pm
Cold mornings (down to 49°F, floor is 50°F) — wait for the surface to warm past midday before you stain.
- Dew margin
- -3.4°F
- Overnight dew
- High
- Rain
- 3%
- Window
- —
High condensation risk overnight — surface dips to within -3.4°F of the 57°F dew point (low 54°F, 52% cloud, 7 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 18.3°F
- Overnight dew
- Low
- Rain
- 1%
- Window
- 9am–5pm
Clear to stain: temps 61–71°F, RH under 78%, surface stays 18.3°F+ above the dew point, no rain in the cure window.
- High condensation risk overnight — surface dips to within 4.2°F of the 40°F dew point (low 42°F, 0% 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.
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.