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Roof Coating Weather in Colorado: Best Months by City

Roof Coating season in Colorado, city by city: peak months, season boundaries, and annual workable-day counts from NOAA 1991–2020 normals. Lakewood leads with 110 workable days a year; Longmont runs the shortest at 83.

Colorado is not one climate: Lakewood banks 110 workable roof coating days a year while Longmont gets 83 — a spread the table below itemizes month by month. Season boundaries mark the first and last month averaging 8+ workable days against the label rules (50–90°F, nights 40°F+).

Statewide, September is the strongest month — it tops or ties the table in most listed cities. The live strips on each city page decide the week; this table decides the month. Scoring rules: methodology; the national playbook: the roof coating guide.

Cities in Colorado

Peak months and season boundaries from NOAA 1991–2020 normals; season = months with at least 8 workable days.
CityPeak monthsSeasonWorkable days/yr
Denver Sep, Aug, Jun May–June 94
Colorado Springs Sep, Jun, Aug May–September 104
Aurora Sep, Aug, Jun May–June 94
Fort Collins Sep, Aug, Jul May–September 108
Lakewood Sep, Jul, Aug May–September 110
Thornton Sep, Jun, Aug May–June 92
Grand Junction May, Sep, Jun August–October 88
Greeley Sep, Jun, May May–June 86
Arvada Aug, Jul, Sep May–September 103
Pueblo Sep, May, Jun May–June 85
Boulder Sep, Aug, Jul May–September 103
Westminster Sep, Jun, Aug May–June 92
Centennial Sep, Jun, Aug May–September 108
Longmont Aug, Sep, Jun May–June 83
Highlands Ranch Sep, Jun, Aug May–September 108
Lafayette Sep, Jun, Aug May–June 92
Castle Rock Sep, Jul, Jun May–September 106

The rules behind these numbers

Typical label thresholds for roof coating — the single ruleset used by every check on this page.
CheckThresholdWhy it matters
Air temperature 50–90°F Acrylic and elastomeric coatings want 50°F+ during application and initial cure.
Overnight low ≥40°F during the first 24 h Water-based coatings can be ruined by a cold, damp night before they skin over.
Dry before ≤0.05" rain in the prior 24 h; watch back to 48 h The membrane must be dry — coatings trap moisture that later blisters.
Dry after <0.05" rain for 24 h after (48 h thick coats want 48 h) Rain inside 24 hours washes uncured coating into gutters.
Evening dew-point spread ≥5°F from 6–11 pm Roofs radiate heat at night and hit the dew point before anything else in the yard.
Daytime humidity ≤85% Humid air slows water-based coatings dramatically.
Wind ≤15 mph (roller only, no spray up to 20 mph) Wind on a roof is a safety limit first and an overspray limit second.

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

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