Is it good to stain in Missoula, MT this week?
A live 7-day go/no-go calendar for deck & fence stain in Missoula, 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
- 10.4°F
- Overnight dew
- Low
- Rain
- 2%
- Window
- —
Humidity peaks at 96% — well above the 85% ceiling; cure stalls and moisture gets trapped.
- Dew margin
- 12.2°F
- Overnight dew
- Low
- Rain
- 2%
- 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
- 8.6°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 8am–5pm
Clear to stain: temps 52–76°F, RH under 46%, surface stays 8.6°F+ above the dew point, no rain in the cure window.
- Dew margin
- 15.5°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 9am–5pm
Cold mornings (down to 47°F, floor is 50°F) — wait for the surface to warm past midday before you stain.
- Dew margin
- 6.4°F
- Overnight dew
- Low
- Rain
- 1%
- Window
- 8am–5pm
Clear to stain: temps 52–84°F, RH under 48%, surface stays 6.4°F+ above the dew point, no rain in the cure window.
- Dew margin
- 14.7°F
- Overnight dew
- Low
- Rain
- 1%
- Window
- 9am–5pm
Cold mornings (down to 48°F, floor is 50°F) — wait for the surface to warm past midday before you stain.
- Dew margin
- 28.2°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 10am–5pm
Cold mornings (down to 47°F, floor is 50°F) — wait for the surface to warm past midday before you stain.
- Humidity peaks at 96% — well above the 85% ceiling; cure stalls and moisture gets trapped.
- Cold mornings (down to 41°F, floor is 50°F) — wait for the surface to warm past midday before you stain.
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.