Is it good to stain in Rapid City, SD this week?
A live 7-day go/no-go calendar for deck & fence stain in Rapid City, 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
- 4.3°F
- Overnight dew
- Watch
- Rain
- 41%
- Window
- 8am–5pm
Watch overnight dew — surface comes within 4.3°F of the dew point (margin is 5°F). Time the coat to dry well before evening.
- Dew margin
- 8.2°F
- Overnight dew
- Low
- Rain
- 2%
- Window
- 8am–5pm
Clear to stain: temps 67–82°F, RH under 31%, surface stays 8.2°F+ above the dew point, no rain in the cure window.
- Dew margin
- 6.8°F
- Overnight dew
- Low
- Rain
- 19%
- Window
- 8am–5pm
Hot afternoon (93°F, ceiling 90°F) — stain early and follow the shade.
- Dew margin
- 12.2°F
- Overnight dew
- Low
- Rain
- 27%
- Window
- 8am–5pm
Clear to stain: temps 66–86°F, RH under 60%, surface stays 12.2°F+ above the dew point, no rain in the cure window.
- Dew margin
- 4.6°F
- Overnight dew
- Watch
- Rain
- 32%
- Window
- —
Rain likely in the 24h cure window (32% chance, ~1.1mm) — it can wash out or mar an uncured stain.
- Dew margin
- 11.2°F
- Overnight dew
- Low
- Rain
- 24%
- Window
- —
Too hot — high of 98°F is well over the 90°F ceiling; the film skins over before it can level or adhere.
- Dew margin
- 26.7°F
- Overnight dew
- Low
- Rain
- 29%
- Window
- 8am–5pm
Clear to stain: temps 75–87°F, RH under 38%, surface stays 26.7°F+ above the dew point, no rain in the cure window.
- Watch overnight dew — surface comes within 4.3°F of the dew point (margin is 5°F). Time the coat to dry well before evening.
- Some rain risk (41%) during the cure window — re-check the radar before you start.
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.