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Roof Coating Weather in California: Best Months by City

Roof Coating season in California, city by city: peak months, season boundaries, and annual workable-day counts from NOAA 1991–2020 normals. Mission Viejo leads with 334 workable days a year; Lancaster runs the shortest at 121.

California is not one climate: Mission Viejo banks 334 workable roof coating days a year while Lancaster gets 121 — 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, May 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 California

Peak months and season boundaries from NOAA 1991–2020 normals; season = months with at least 8 workable days.
CityPeak monthsSeasonWorkable days/yr
Los Angeles Aug, Jul, Sep year-round 331
San Francisco Aug, Jul, Sep year-round 295
San Diego Jul, Aug, Jun year-round 316
Riverside Oct, May, Nov October–June 240
Sacramento Oct, May, Apr September–June 220
San Jose Jul, Aug, Sep year-round 301
Fresno Oct, May, Nov January–June 201
Mission Viejo Aug, Jul, May year-round 334
Bakersfield Oct, May, Apr February–June 179
Concord Jul, Aug, Jun year-round 309
Long Beach Aug, Jul, Sep year-round 331
Oakland Jul, Aug, Sep year-round 303
Stockton Oct, May, Apr February–June 172
Oxnard Jul, Aug, Jun year-round 322
Indio Mar, Apr, Nov February–April 129
Victorville May, Oct, Apr March–June 131
Modesto Oct, May, Apr February–June 182
Anaheim Aug, Jul, Sep year-round 331
Antioch Aug, Jul, Sep year-round 297
Santa Ana Aug, Jul, Sep year-round 331
Irvine Aug, Jul, Sep year-round 334
Santa Rosa Jul, Aug, Sep February–November 239
Chula Vista Aug, Jul, Jun year-round 314
Santa Clarita May, Oct, Apr September–June 250
Fremont Jul, Aug, Sep year-round 306
San Bernardino Oct, May, Nov October–June 216
Fontana May, Oct, Apr September–June 246
Moreno Valley Oct, May, Nov October–June 216
Thousand Oaks Jul, Aug, Jun year-round 330
Santa Barbara Aug, Jul, Sep year-round 326
Huntington Beach Aug, Jul, Jun year-round 325
Glendale Aug, Jul, Sep year-round 331
Hemet Oct, May, Apr January–June 208
Ontario May, Oct, Apr September–June 246
Elk Grove Oct, May, Apr February–June 191
Rancho Cucamonga May, Oct, Apr September–June 246
Salinas Jul, Aug, Sep year-round 310
Vallejo Jul, Aug, Sep February–November 244
Oceanside Aug, Jul, Jun January–November 295
Garden Grove Aug, Jul, Sep year-round 331
Lancaster May, Oct, Apr March–June 121
Visalia Oct, May, Apr February–June 192
Palmdale May, Oct, Apr March–June 142
Santa Cruz Jul, Aug, Sep year-round 300
Merced May, Oct, Apr March–June 160
Corona May, Oct, Apr October–June 240
Hayward Jul, Aug, Jun year-round 306
Roseville May, Oct, Apr February–June 164
Sunnyvale Aug, Jul, Sep year-round 300
Fairfield Jul, Aug, Sep year-round 289
Escondido Aug, Jul, Sep year-round 324
Pomona May, Jun, Oct September–July 274
Santa Maria Aug, Jul, Jun year-round 306
Torrance Aug, Jul, May year-round 332
Fullerton Aug, Jul, Jun year-round 328
Orange Aug, Jul, Sep year-round 331
Pasadena Jul, Oct, Jun September–July 276
Santa Clara Jul, Aug, Sep year-round 301
Simi Valley May, Oct, Apr October–June 233
Clovis Oct, May, Nov January–June 201
Yuba City May, Oct, Apr February–June 161
Seaside Jul, Aug, Sep year-round 297
Berkeley Jul, Aug, Sep year-round 299
Redding Oct, May, Apr February–June 133
Gilroy Aug, Jul, Sep February–November 255
Richmond Jul, Aug, Sep year-round 299
Carlsbad Jul, Aug, Jun year-round 313
Murrieta Aug, Jul, Sep year-round 317
East Los Angeles Aug, Jul, Sep year-round 333
Temecula Aug, Jul, Sep year-round 317
Downey Aug, Jul, Sep year-round 331
Costa Mesa Aug, Jul, Jun year-round 325
Menifee May, Oct, Apr October–June 224
San Buenaventura Jul, Aug, Jun year-round 322
Chico Sep, Jun, Oct January–June 230
West Covina May, Jun, Oct September–July 274
Jurupa Valley May, Oct, Apr September–June 246
El Monte Aug, Jul, Sep year-round 333
Inglewood Aug, Jul, Jun year-round 328
Burbank Aug, Jul, Sep year-round 331
El Cajon Aug, Jul, Sep year-round 330
Rialto Oct, May, Nov October–June 238
San Mateo Jul, Aug, Sep year-round 300
Vacaville May, Oct, Apr February–June 158
Daly City Jul, Aug, Jun year-round 300
Hesperia May, Oct, Apr March–June 131
Norwalk Aug, Jul, Jun year-round 328
Vista Aug, Jul, Sep year-round 322
Tracy May, Oct, Apr September–June 211
Arden-Arcade Oct, May, Apr September–June 220
San Marcos Aug, Jul, Sep year-round 324
Manteca Oct, May, Apr February–June 171
Carson Aug, Jul, May year-round 332
Compton Aug, Jul, Jun year-round 328
Chino May, Oct, Apr October–June 240
South Gate Aug, Jul, Sep year-round 332
Santa Monica Aug, Jul, May year-round 333
Westminster Aug, Jul, Sep year-round 331
San Leandro Jul, Aug, Jun year-round 306
Citrus Heights Oct, May, Apr September–June 220
Lake Forest Jul, Jun, May year-round 314
Whittier Aug, Jul, Jun year-round 328
San Ramon Aug, Jul, Sep year-round 297
Livermore Jul, Aug, Jun February–November 249
Hawthorne Aug, Jul, Jun year-round 328
Folsom Oct, May, Apr September–June 220
Newport Beach Aug, Jul, May year-round 331
Mountain View Aug, Jul, Sep year-round 300
Madera May, Oct, Apr February–June 168
Buena Park Aug, Jul, Jun year-round 328
Redwood City Jul, Aug, Sep year-round 296
Napa Aug, Jul, Sep January–November 275
Rancho Cordova Oct, May, Apr September–June 220
Alhambra Aug, Jul, Sep year-round 333
Perris May, Oct, Apr October–June 224
Lakewood Aug, Jul, Sep year-round 331
Turlock Oct, May, Sep September–June 239
Upland May, Jun, Oct September–July 274

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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