Is it good to stain in Manchester, NH this week?
A live 7-day go/no-go calendar for deck & fence stain in Manchester, 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
- 1.6°F
- Overnight dew
- High
- Rain
- 7%
- Window
- —
High condensation risk overnight — surface dips to within 1.6°F of the 61°F dew point (low 60°F, 100% cloud, 5 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 4.3°F
- Overnight dew
- Watch
- Rain
- 18%
- Window
- 10am–2pm
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
- -1.7°F
- Overnight dew
- High
- Rain
- 1%
- Window
- —
High condensation risk overnight — surface dips to within -1.7°F of the 45°F dew point (low 42°F, 4% cloud, 4 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- -0.1°F
- Overnight dew
- High
- Rain
- 13%
- Window
- —
High condensation risk overnight — surface dips to within -0.1°F of the 52°F dew point (low 47°F, 100% cloud, 3 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Dew margin
- 9.8°F
- Overnight dew
- Low
- Rain
- 11%
- Window
- 10am–5pm
High humidity (92%, over the 85% mark) slows drying — keep an eye on the cure window.
- Dew margin
- 10.3°F
- Overnight dew
- Low
- Rain
- 1%
- Window
- 12pm–5pm
Cold mornings (down to 41°F, floor is 50°F) — wait for the surface to warm past midday before you stain.
- Dew margin
- 5.5°F
- Overnight dew
- Low
- Rain
- 0%
- Window
- 10am–5pm
Cold mornings (down to 41°F, floor is 50°F) — wait for the surface to warm past midday before you stain.
- High condensation risk overnight — surface dips to within 1.6°F of the 61°F dew point (low 60°F, 100% cloud, 5 mph wind). A fresh stain can blush/blister. Stop 4h before dew falls.
- Humidity peaks at 99% — well above the 85% ceiling; cure stalls and moisture gets trapped.
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.