Is it good to coat in Chicago, IL this week?
A live 7-day go/no-go calendar for epoxy & resin floors in Chicago, 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
- 2.3°F
- Overnight dew
- Watch
- Rain
- 1%
- Window
- 10am–5pm
Watch overnight dew — surface comes within 2.3°F of the dew point (margin is 5°F). Time the coat to dry well before evening.
- Dew margin
- -2.5°F
- Overnight dew
- High
- Rain
- 1%
- Window
- —
High condensation risk overnight — surface dips to within -2.5°F of the 54°F dew point (low 50°F, 100% cloud, 2 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Dew margin
- 11.2°F
- Overnight dew
- Low
- Rain
- 19%
- Window
- 9am–5pm
Clear to coat: temps 61–76°F, RH under 74%, surface stays 11.2°F+ above the dew point, no rain in the cure window.
- Dew margin
- 1.1°F
- Overnight dew
- High
- Rain
- 44%
- Window
- —
High condensation risk overnight — surface dips to within 1.1°F of the 65°F dew point (low 66°F, 100% cloud, 12 mph wind). A fresh coat can blush/blister. Stop 4h before dew falls.
- Dew margin
- 6.4°F
- Overnight dew
- Low
- Rain
- 67%
- Window
- —
Humidity peaks at 96% — well above the 85% ceiling; cure stalls and moisture gets trapped.
- Dew margin
- 12.1°F
- Overnight dew
- Low
- Rain
- 29%
- Window
- 8am–5pm
Clear to coat: temps 57–65°F, RH under 40%, surface stays 12.1°F+ above the dew point, no rain in the cure window.
- Dew margin
- 12.7°F
- Overnight dew
- Low
- Rain
- 9%
- Window
- 8am–5pm
Clear to coat: temps 52–60°F, RH under 51%, surface stays 12.7°F+ above the dew point, no rain in the cure window.
- Watch overnight dew — surface comes within 2.3°F of the dew point (margin is 5°F). Time the coat to dry well before evening.
- High humidity (89%, over the 85% mark) slows drying — keep an eye on the cure window.
Caution. 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.