WorkWindow

Exterior Painting Weather in Iowa: Best Months by City

Exterior Painting season in Iowa, city by city: peak months, season boundaries, and annual workable-day counts from NOAA 1991–2020 normals. Des Moines leads with 129 workable days a year; Sioux City runs the shortest at 114.

Across Iowa's 6 listed cities, annual workable days for exterior painting run from 114 (Sioux City) up to 129 (Des Moines). Every number comes from NOAA 1991–2020 normals scored against the same label ruleset; every city name links to its live 10-day check.

If one month anchors the Iowa calendar it's August, the statewide leader in workable days. Use this page to pick the month, then the city page's 10-day strip to pick the days — and the national exterior painting guide for the physics behind each rule.

Cities in Iowa

Peak months and season boundaries from NOAA 1991–2020 normals; season = months with at least 8 workable days.
CityPeak monthsSeasonWorkable days/yr
Des Moines Aug, Sep, Jul April–October 129
Davenport Aug, Jul, Sep May–October 125
Cedar Rapids Aug, Sep, Jul May–October 115
Iowa City Jul, Aug, Sep April–October 122
Waterloo Aug, Jul, Sep May–October 119
Sioux City Sep, Aug, Jul May–October 114

The rules behind these numbers

Typical label thresholds for exterior painting — the single ruleset used by every check on this page.
CheckThresholdWhy it matters
Air temperature 50–90°F (low-temp formulas from 35°F) Standard latex wants 50°F+. Some low-temperature formulas are rated down to 35°F.
Overnight low ≥35°F during the first 24 h (≥40°F preferred) Paint keeps curing overnight; a low under 40°F stalls standard latex.
Dry before ≤0.05" rain in the prior 12 h; watch back to 24 h The surface must be dry to the touch and out of a recent soak.
Dry after <0.05" rain for 24 h after Rain inside the first 24 hours can streak or wash fresh paint.
Evening dew-point spread ≥5°F from 6–11 pm Surface should stay at least 5°F above the dew point; dew flat-spots fresh paint.
Daytime humidity ≤80% High humidity extends recoat and cure times.
Wind ≤15 mph (brush only up to 20 mph) Wind dries the leading edge too fast and carries overspray.

Always follow your product label — formulas vary. The table above is the typical range across major manufacturers, not a promise about your can.

Other tasks in Iowa

More