Is it good to stain in Sioux City, IA this week?
A live 7-day go/no-go calendar for deck & fence stain in Sioux 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
- 0.2°F
- Overnight dew
- High
- Rain
- 11%
- Window
- —
High condensation risk overnight — surface dips to within 0.2°F of the 74°F dew point (low 71°F, 4% cloud, 9 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- -0.4°F
- Overnight dew
- High
- Rain
- 83%
- Window
- —
High condensation risk overnight — surface dips to within -0.4°F of the 74°F dew point (low 68°F, 100% cloud, 15 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.3°F
- Overnight dew
- High
- Rain
- 56%
- Window
- —
High condensation risk overnight — surface dips to within 0.3°F of the 68°F dew point (low 69°F, 100% cloud, 4 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 3.4°F
- Overnight dew
- Watch
- Rain
- 30%
- Window
- —
Humidity peaks at 97% — well above the 85% ceiling; cure stalls and moisture gets trapped.
- Dew margin
- -0.9°F
- Overnight dew
- High
- Rain
- 39%
- Window
- —
High condensation risk overnight — surface dips to within -0.9°F of the 73°F dew point (low 68°F, 100% cloud, 6 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- -3.3°F
- Overnight dew
- High
- Rain
- 14%
- Window
- —
High condensation risk overnight — surface dips to within -3.3°F of the 63°F dew point (low 59°F, 99% cloud, 6 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 8.2°F
- Overnight dew
- Low
- Rain
- 11%
- Window
- —
Rain likely in the 24h cure window (11% chance, ~2.1mm) — it can wash out or mar an uncured stain.
- High condensation risk overnight — surface dips to within 0.2°F of the 74°F dew point (low 71°F, 4% cloud, 9 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Hot afternoon (93°F, ceiling 90°F) — stain early and follow the shade.
- High humidity (92%, over the 85% mark) slows drying — keep an eye on the cure window.
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.