Northern California Flying Weather
CA · 2006–2025 · 24 eligible airports
A varied maritime-and-mountain regime: summer marine stratus brings frequent morning IFR to Bay Area and coastal airports with gusty onshore sea breezes funneling through the Golden Gate and coastal gaps, while the redwood North Coast around Arcata sees persistent fog and low ceilings in nearly every season. Winter Pacific storms bring rain, low ceilings, strong southerly winds, and heavy snow with airframe icing over the Sierra and northern mountains. The Sierra counties add high terrain, summer density altitude, lee-side mountain wave, and infrequent summer afternoon thunderstorms; summer wildfire smoke can sharply reduce visibility region-wide. Fall is typically the best flying season; winter storm cycles and summer coastal stratus mornings are the worst.
- Daylight VFR
- 82.2%
- VFR days/yr
- 283
- Mean wind
- 5.3 kt
- Most VFR month
- October
- Fewest VFR month
- December
- VFR Score
- 58
Regional standouts
VFR conditions by month
Regional average across eligible airports
| Month | VFR % |
|---|---|
| Jan | 76.1% |
| Feb | 80.9% |
| Mar | 81.7% |
| Apr | 83.1% |
| May | 79.5% |
| Jun | 82.2% |
| Jul | 78.0% |
| Aug | 76.2% |
| Sep | 81.1% |
| Oct | 83.9% |
| Nov | 80.6% |
| Dec | 73.9% |
Average wind by month
Regional average sustained wind
| Month | Mean wind (kt) |
|---|---|
| Jan | 4.3 kt |
| Feb | 5.1 kt |
| Mar | 5.7 kt |
| Apr | 6.0 kt |
| May | 6.4 kt |
| Jun | 6.4 kt |
| Jul | 6.0 kt |
| Aug | 5.5 kt |
| Sep | 4.9 kt |
| Oct | 4.4 kt |
| Nov | 4.1 kt |
| Dec | 4.4 kt |
Every airport in Northern California, ranked
Sort by any column. Best VFR Score first.
| KCECJack Mc Namara Field Airport | Crescent City | 56.0 | 25.5 | 170 | 6 kt | 12 |
| KACVCalifornia Redwood Coast-Humboldt County Airport | Arcata/Eureka | 58.8 | 24.5 | 176 | 4 kt | 16 |
| KMRYMonterey Regional Airport | Monterey | 67.6 | 18.1 | 255 | 5 kt | 36 |
| KSNSSalinas Municipal Airport | Salinas | 70.0 | 15.2 | 276 | 6 kt | 37 |
| KWVIWatsonville Municipal Airport | Watsonville | 69.2 | 19.0 | 269 | 3 kt | 44 |
| KOAKOakland San Francisco Bay Airport | Oakland | 75.8 | 8.2 | 291 | 7 kt | 51 |
| KSTSCharles M. Schulz Sonoma County Airport | Santa Rosa | 72.8 | 17.6 | 287 | 3 kt | 51 |
| KHWDHayward Executive Airport | Hayward | 76.4 | 6.3 | 288 | 5 kt | 54 |
| KDVOMarin County Airport - Gnoss Field | Novato | 78.0 | 10.1 | 273 | 4 kt | 55 |
| KSFOSan Francisco International Airport | San Francisco | 79.5 | 5.4 | 288 | 8 kt | 56 |
| KAPCNapa County Airport | Napa | 78.5 | 10.4 | 295 | 6 kt | 57 |
| KBLUBlue Canyon Nyack Airport | Emigrant Gap | 81.6 | 13.4 | 278 | 4 kt | 59 |
| KCVHHollister Municipal Airport | Hollister | 79.4 | 8.4 | 298 | 4 kt | 61 |
| KTRKTruckee Tahoe Airport | Truckee | 84.3 | 8.2 | 248 | 3 kt | 65 |
| KCCRBuchanan Field | Concord | 87.2 | 3.5 | 302 | 6 kt | 69 |
| KLVKLivermore Municipal Airport | Livermore | 84.9 | 3.9 | 308 | 5 kt | 70 |
| KUKIUkiah Municipal Airport | Ukiah | 85.5 | 4.9 | 299 | 0 kt | 72 |
| KAUNAuburn Municipal Airport | Auburn | 88.6 | 5.4 | 303 | 5 kt | 74 |
| KSJCNorman Y. Mineta San Jose International Airport | San Jose | 86.5 | 2.7 | 325 | 5 kt | 74 |
| KAATAlturas Municipal Airport | Alturas | 89.0 | 2.6 | 307 | 3 kt | 77 |
| KTVLLake Tahoe Airport | South Lake Tahoe | 89.8 | 4.6 | 308 | 4 kt | 77 |
| KVCBNut Tree Airport | Vacaville | 90.9 | 3.9 | 312 | 5 kt | 78 |
| KLHMLincoln Regional Karl Harder Field | Lincoln | 90.4 | 4.1 | 313 | 5 kt | 79 |
| KSIYSiskiyou County Airport | Montague | 92.9 | 3.5 | 319 | 4 kt | 82 |
The pattern in Northern California
Across 2006–2025, the 24 eligible airports in Northern California reported VFR conditions during about 82.2% of valid daytime observations, with an estimated 283 VFR flying days per year and a mean surface wind of 5.3 kt. KSIY (Siskiyou County Airport) had the most VFR weather at 93.1%. KCEC saw the most instrument conditions, at 25.5% IFR/LIFR. The lowest-ranked eligible field by VFR Score was KCEC (Jack Mc Namara Field Airport).
Neighboring regions
How Northern California is defined
CA counties: Del Norte, Humboldt, Mendocino, Lake, Sonoma, Napa, Marin, Solano, Contra Costa, Alameda, San Francisco, San Mateo, Santa Clara, Santa Cruz, San Benito, Monterey, Siskiyou, Trinity, Modoc, Lassen, Plumas, Sierra, Nevada, Placer, El Dorado, Alpine, Amador, Calaveras, Tuolumne, Mariposa. (All CA counties NOT assigned to southern-california-coast, southern-california-inland, or california-central-valley — the valley counties Shasta, Tehama, Glenn, Butte, Colusa, Sutter, Yuba, Yolo, Sacramento, San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare, and Kern belong to california-central-valley.)
Educational use only. Historical weather rankings from ATIS Alerts are educational summaries of past observations — not a forecast, flight-planning tool, or safety rating. They do not replace current METARs, TAFs, NOTAMs, ATIS, or a weather briefing, and favorable history does not make any airport safe. Always check current conditions and use your own judgment before flight.