Is it good to coat in St. Paul, MN this week?
A live 7-day go/no-go calendar for epoxy & resin floors in St. Paul, 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°F
- Overnight dew
- High
- Rain
- 64%
- Window
- —
High condensation risk overnight — surface dips to within 0°F of the 73°F dew point (low 73°F, 95% cloud, 9 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Dew margin
- -2.8°F
- Overnight dew
- High
- Rain
- 50%
- Window
- —
High condensation risk overnight — surface dips to within -2.8°F of the 75°F dew point (low 72°F, 100% cloud, 5 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Dew margin
- 1.7°F
- Overnight dew
- High
- Rain
- 35%
- Window
- —
High condensation risk overnight — surface dips to within 1.7°F of the 73°F dew point (low 74°F, 100% cloud, 6 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.6°F
- Overnight dew
- High
- Rain
- 74%
- Window
- —
High condensation risk overnight — surface dips to within 0.6°F of the 74°F dew point (low 73°F, 7% cloud, 6 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Dew margin
- 0.3°F
- Overnight dew
- High
- Rain
- 55%
- Window
- —
High condensation risk overnight — surface dips to within 0.3°F of the 71°F dew point (low 70°F, 23% cloud, 8 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Dew margin
- -1.9°F
- Overnight dew
- High
- Rain
- 38%
- Window
- —
High condensation risk overnight — surface dips to within -1.9°F of the 74°F dew point (low 72°F, 84% cloud, 7 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Dew margin
- 6.5°F
- Overnight dew
- Low
- Rain
- 46%
- Window
- —
Too hot — high of 94°F is well over the 86°F ceiling; the film skins over before it can level or adhere.
- High condensation risk overnight — surface dips to within 0°F of the 73°F dew point (low 73°F, 95% cloud, 9 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Rain likely in the 24h cure window (64% chance) — it can wash out or mar an uncured coat.
- High humidity (90%, 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
Installing within 5°F of the dew point causes amine blush / carbamation — a cloudy, greasy, hazed floor. The slab surface temp, not the air, is what counts.
- • Surface temp must stay 5°F above the dew point through application and cure (ASTM D3276 / ISO 8502-42).
- • Air + surface in the 50–86°F band (low-temp lines to 50°F).
- • Humidity under 85%; ideally under 80%.
- • 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.