Is it good to stain in Columbia, MD this week?
A live 7-day go/no-go calendar for deck & fence stain 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
- 5°F
- Overnight dew
- Low
- Rain
- 26%
- Window
- 8am–5pm
Clear to stain: temps 72–86°F, RH under 82%, surface stays 5°F+ above the dew point, no rain in the cure window.
- Dew margin
- 2.5°F
- Overnight dew
- High
- Rain
- 15%
- Window
- —
High condensation risk overnight — surface dips to within 2.5°F of the 67°F dew point (low 70°F, 5% cloud, 4 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 7.9°F
- Overnight dew
- Low
- Rain
- 35%
- Window
- 8am–5pm
Some rain risk (35%) during the cure window — re-check the radar before you start.
- Dew margin
- 13.4°F
- Overnight dew
- Low
- Rain
- 35%
- Window
- 8am–5pm
Some rain risk (35%) during the cure window — re-check the radar before you start.
- Dew margin
- 14.3°F
- Overnight dew
- Low
- Rain
- 9%
- Window
- 8am–5pm
Clear to stain: temps 67–84°F, RH under 59%, surface stays 14.3°F+ above the dew point, no rain in the cure window.
- Dew margin
- 1.2°F
- Overnight dew
- High
- Rain
- 48%
- Window
- —
High condensation risk overnight — surface dips to within 1.2°F of the 72°F dew point (low 74°F, 100% cloud, 8 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 13.4°F
- Overnight dew
- Low
- Rain
- 24%
- Window
- 9am–5pm
High humidity (87%, over the 85% mark) slows drying — keep an eye on the cure window.
- Clear to stain: temps 72–86°F, RH under 82%, surface stays 5°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
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.