Fairfield Weather
Town • San Francisco Bay Area
Fairfield spreads across the flats where Interstate 80 comes out of the southern Solano hills. It lies about 45 miles from both San Francisco and Sacramento and 15 miles from Napa Valley. Suisun City and the edge of Suisun Marsh lie immediately south, and the Suisun Valley wine district runs northwest toward Napa. Rockville Hills Regional Park covers the oak and grassland hills on the west side. Of the Solano towns in this area, it sits most directly in the path of air coming through the Carquinez Strait.
Plan your week
10-Day Forecast
Hour by hour
Hourly Forecast
Current Conditions
Comfort Breakdown
Fairfield weather today and through the year
It's 52°F at Fairfield right now (feels like 51°F), with 1 mph wind and a comfort score of 76. Monday's forecast high at Fairfield is 57°F, 9°F below the mid November normal of 66°F. The best window today is 9 AM to noon, at about 53°F with a 7 mph wind (comfort 59).
July is the warmest month at Fairfield, with an average high of 89°F. December is the coldest, with an average low of 39°F. December is the wettest month (4.4 in.), out of about 21.1 in. a year. By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Fairfield are June, September, and August. The best hours are usually 9 AM to noon in June, 9 AM to noon in September, and 9 AM to noon in August.
Fairfield's weather starts at the Carquinez Strait, the sea-level break in the Coast Ranges that lets Pacific air reach the Central Valley. As the valley heats on summer afternoons, cooler air from San Francisco Bay is pulled east through the strait and across Suisun Bay. Fairfield sits right in that stream, so a strong west or southwest wind in the afternoon is the normal summer pattern here, not an occasional event.
Forecast updated November 15, 2026 at 4:00 AM PST. Climate figures come from NOAA 1991-2020 normals. Hourly patterns come from NOAA's HRRR hourly analysis from September 2014 to April 2026.
What to expect at Fairfield in the next few days
No active National Weather Service alerts for this location.
Best time to go
The best window today is 9 AM to noon, at about 53°F with a 7 mph wind (comfort 59).
Best day this week
Of the next 7 days, Friday looks best for Fairfield, with a 61°F high and midday comfort near 77. Wednesday looks weakest (41).
Rain
Next good chance of rain: today (75%, about 0.21 in.).
Live weather map
Weather around Fairfield right now
Overcast and 52° at Fairfield right now.
About the live weather map for Fairfield
The map centers on Fairfield and stacks fog, satellite clouds, and precipitation radar on one view. Clouds come from the GOES-West satellite and rain from NOAA radar, and both show current conditions. Fog comes from our HRRR-based fog model, and the slider steps through its forecast for the next 12 hours.
Dots mark nearby places with their current temperature, colored by comfort score. Use the layer buttons to turn any layer off, or open the full map for every destination in the region.
Nearby Temperature Comparison
Conditions at nearby San Francisco Bay Area destinations
Tip: Bay Area temperatures can change by 20 to 30°F over a short distance because of microclimates.
Fairfield vs nearby places
Typical summer conditions compared with Fairfield, from the same NOAA HRRR hourly record. The list shows the closest places, then nearby places whose climate differs the most.
| Place | Distance | Summer afternoons | Morning fog | Afternoon wind | Compared with Fairfield |
|---|---|---|---|---|---|
| Suisun City | 0.8 mi | same | 5% | 11 mph | same 3 km weather-model cell, so our hourly data cannot tell them apart |
| Vacaville | 7.9 mi | +5°F | 1% | 9 mph | about 5°F warmer on summer afternoons |
| Wooden Valley | 9.9 mi | -1°F | 3% | 10 mph | about 34% more rain a year |
| American Canyon | 13.1 mi | -8°F | 20% | 11 mph | about 8°F cooler on summer afternoons and more summer morning fog (20% vs 5% of morning hours) |
| Yountville | 20.3 mi | +2°F | 29% | 8 mph | more summer morning fog (29% vs 5% of morning hours) and about 30% more rain a year |
| Briones Regional Park | 22.6 mi | -8°F | 23% | 11 mph | about 8°F cooler on summer afternoons and more summer morning fog (23% vs 5% of morning hours) |
Places with a climate like Fairfield's
- Pittsburg (18 mi away): nearly the same temperatures every month
- Birds Landing (12 mi away): nearly the same temperatures every month
- Antioch (21 mi away): nearly the same temperatures every month
Climate Dashboard
Current conditions vs. NOAA normals and recent destination baseline
What the Fairfield climate comparisons mean
These cards compare recent conditions at Fairfield with the available local baseline. Temperature and year-to-date rainfall use long-term normals when available. Fog, sunshine, wind, and comfort use the matching recent or modeled baseline identified on each card.
Positive and negative differences describe how Fairfield departs from its own usual pattern. They should not be read as a direct comparison with another city or as a forecast beyond the period shown.
Fairfield weather by month
July is the warmest month at Fairfield, with an average high of 89°F. December is the coldest, with an average low of 39°F. December is the wettest month (4.4 in.), out of about 21.1 in. a year. Morning fog peaks in December, when fog or low cloud covers 30% of the hours from 6 to 10 AM. July has the clearest middays, with clouds covering about 4% of the sky from 11 AM to 3 PM.
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Fairfield are June, September, and August. The best hours are usually 9 AM to noon in June, 9 AM to noon in September, and 9 AM to noon in August.
| Month | Avg high | Avg low | Rain | Rainy days | Morning fog | Midday cloud | Afternoon wind | Daylight | Comfort |
|---|---|---|---|---|---|---|---|---|---|
| Jan | 57°F | 40°F | 4.3 in | 9 | 28% | 34% | 6 mph | 9.8 h | 58 |
| Feb | 62°F | 42°F | 4.1 in | 8 | 12% | 22% | 7 mph | 10.7 h | 63 |
| Mar | 67°F | 45°F | 2.9 in | 7 | 7% | 26% | 8 mph | 11.9 h | 68 |
| Apr | 72°F | 47°F | 1.3 in | 5 | 5% | 19% | 9 mph | 13.2 h | 79 |
| May | 78°F | 52°F | 0.7 in | 3 | 6% | 13% | 11 mph | 14.3 h | 79 |
| Jun | 86°F | 56°F | 0.1 in | 2 | 4% | 5% | 11 mph | 14.8 h | 83 |
| Jul | 89°F | 58°F | 0.0 in | 0 | 7% | 4% | 11 mph | 14.6 h | 80 |
| Aug | 89°F | 57°F | 0.0 in | 1 | 4% | 4% | 10 mph | 13.6 h | 81 |
| Sep | 86°F | 56°F | 0.1 in | 1 | 2% | 7% | 9 mph | 12.3 h | 83 |
| Oct | 78°F | 51°F | 0.9 in | 4 | 4% | 11% | 7 mph | 11.1 h | 81 |
| Nov | 66°F | 44°F | 2.2 in | 6 | 11% | 22% | 6 mph | 10.0 h | 76 |
| Dec | 57°F | 39°F | 4.4 in | 9 | 30% | 37% | 6 mph | 9.5 h | 54 |
Morning fog is the share of hours from 6 to 10 AM with fog or low cloud. Midday cloud is the average from 11 AM to 3 PM, and afternoon wind is the average from 1 to 5 PM. The highlighted rows are the most comfortable months.
What makes Fairfield's weather different
When the fog burns off
34%of 7 AM hours foggy in December
Fog or low cloud covers Fairfield in 34% of 7 AM hours in December, the foggiest month. It thins slowly and often lasts into the early afternoon. September mornings are the least foggy (2%).
When the wind picks up
2 PMwhen afternoon wind builds, March–September
From March through September, wind at Fairfield typically builds after 2 PM. In June it peaks around 5 PM, averaging 13 mph with 20% of those hours windy, while mornings average 9 mph.
Hot hours
4 habove 85°F on a typical July afternoon
In July, the average temperature stays at or above 85°F for 4 hours a day.
Microclimate
+5°FVacaville, 7.9 mi away, on summer afternoons
Vacaville, 7.9 miles away, runs about 5°F warmer than Fairfield on summer afternoons.
Model resolution
2 placesshare one 3 km NOAA HRRR grid cell
Fairfield shares one 3 km grid cell in NOAA's HRRR model with Suisun City. The hourly fog, wind, cloud, and temperature patterns on this site are the same for both. Real differences between them come from hills, elevation, and wind exposure that the model cannot resolve.
Daylight
9.5–14.8 hof daylight, Dec to Jun
Days at Fairfield range from about 9.5 hours in December to 14.8 hours in June. In mid-June the sun sets around 8:32 PM, and in mid-December around 4:53 PM.
Seasons at Fairfield
- Warm seasonJun 25 – Sep 23 · highs 86°F+
The warm season lasts about 3 months, from Jun 25 to Sep 23, when the average high is 86°F or warmer. Highs peak around Jul 8 at about 89°F.
- Hot afternoonsJun 7 – Sep 25 · highs 85°F+
Average highs reach 85°F or more from Jun 7 to Sep 25.
- Cool seasonNov 26 – Feb 27 · highs 64°F or lower
The cool season runs from Nov 26 to Feb 27, when the average high is 64°F or lower. The coldest nights come around Dec 8, with an average low near 39°F.
- Rainy seasonNov 16 – Mar 29 · 79% of the year's rain
The rainy season runs from Nov 16 to Mar 29, when a day has at least a 20% chance of measurable rain. That stretch brings 79% of the year's rain.
The dark line marks today. Season dates come from the smoothed daily NOAA 1991-2020 normals. Counting from Oct. 1, a typical year has its first inch of rain by Nov 1 and half of its annual total by Jan 23.
Days per year and extremes (Nov 1, 2024 to Oct 31, 2026)
This record runs from Nov 1, 2024 to Oct 31, 2026. Over this record, Fairfield averaged 31 days a year at 90°F or hotter and 1 night a year at or below freezing. It averaged 14 days a year with at least half an inch of rain and 1 afternoon with wind of 20 mph or more at 2 PM. About 56 mornings a year had 3 or more hours of fog or low cloud.
In the same record, the hottest day was Jun 11, 2026 (103°F) and the coldest night was Feb 10, 2025 (31°F). The wettest day was Nov 23, 2024 (2.03 in.), and the strongest 2 PM gust was 42 mph on Feb 13, 2025.
- 31days at 90°F or hotter
- 1night at or below freezing
- 14days with ½ in. of rain or more
- 1afternoon with 20+ mph wind
- 56mornings with 3+ hours of fog or low cloud
- Hottest day103°FJun 11, 2026
- Coldest night31°FFeb 10, 2025
- Wettest day2.03 inNov 23, 2024
- Strongest 2 PM gust42 mphFeb 13, 2025
What shapes Fairfield's weather
Marine air pulled through the Carquinez Strait is why Fairfield usually runs cooler than Vacaville and the valley towns to the north and east on summer afternoons. It is also why evenings cool off quickly. When the marine layer, the sheet of low cloud that forms over the cold ocean, is deep, low clouds can follow the breeze inland overnight. A National Weather Service case study shows the leading edge of that cloud at Travis and Fairfield before it spread up the Sacramento Valley.
The sea breeze pattern breaks down when the wind turns north or northeast. Air sinking off higher terrain warms as it descends, the sea breeze stalls, and Fairfield gets its hottest and driest days. Those north-wind spells also dry out the grass on Rockville Hills and the slopes around Suisun Valley, which raises the fire danger in late summer and fall.
Winter storms come in from the Pacific and bring most of the year's rain from December through February. Between storms the wind often goes light, and on calm, clear nights cold air settles onto the low ground toward the marsh.
Tips for visiting Fairfield
Hike Rockville Hills before the wind
The park covers more than 600 acres of grassland and oak woodland with over 30 miles of trails, open sunrise to sunset. Summer mornings are calmer and cooler than afternoons.
Carry a pass and ID in Rockville Hills
Passes are sold at both entrances, and rangers can cite visitors without a valid pass and ID. Dogs need their own entry fee and must stay leashed on trail.
Expect gusty afternoons
Afternoon westerly winds are common along the Carquinez Strait side of Solano County. Weigh down picnic gear and outdoor tables after midday.
Head into Suisun Valley for tasting
The valley just outside town is a designated wine region with about 10 wineries plus farm stands selling fruit, nuts, and local olive oil.
Skip I-80 traffic by train
Capitol Corridor trains stop at both Suisun-Fairfield and Fairfield-Vacaville Hannigan stations.
Fairfield through the seasons
- Spring (March–May)
- Spring brings green hills and the best hiking weather in Rockville Hills. The afternoon west wind starts to build as the valley warms.
- Summer (June–August)
- Summer afternoons are hot, tempered almost every day by marine air pulled through the Carquinez Strait. On the few days that flow weakens, ozone, a lung irritant that forms in hot sunshine, can climb above health standards.
- Fall (September–October)
- The sea breeze weakens, so still, warm days and dry north-wind spells become more likely. Grass on the hills is at its driest until the first real rain.
- Winter (November–February)
- Winter storms bring most of the year's rain, and calm nights between them turn cold on the low ground toward the marsh.
Activities and the weather that matters
- Mountain biking and hiking in Rockville Hills: Best on cool spring and fall mornings. Summer afternoons are hot and windy, so start early and carry water.
- Wine tasting in Suisun Valley: Good on almost any dry day. The city's visitor bureau notes that local winds cool the valley, which takes the edge off summer heat.
- Cycling the wine-country back roads: Ride in the morning. The afternoon west wind can turn the trip home into a long headwind grind.
Official sources and current conditions
- Visit Fairfield: Rockville Hills Park
- Capitol Corridor stations
- National Weather Service Sacramento
- Alert Solano emergency notifications
- Spare the Air (Bay Area air quality)
Numbers on this page come from NOAA data. The text draws on the official sources linked above.
Historical Climate Data
Long-term weather patterns and climate data
Data sources: Recent temperatures come from NOAA URMA and recent precipitation from NOAA Stage IV. Fog, cloud, wind, humidity, and sunshine come from NOAA HRRR, and long-term baselines from NOAA 1991-2020 climate normals.
Climate Overview
Based on NOAA 30-year temperature/rain normals (1991-2020) with recent fog/sun baseline
🌟 Best Months to Visit
⚠️ Challenging Months
Monthly Breakdown
| Month | Comfort | High/Low | ☀️ Sun | 🌫️ Fog | 💧 Rain | Perfect |
|---|---|---|---|---|---|---|
| November 2024 | 80 | 63° / 44.7° | 6.3h | 3d | 4.77" | 18 |
| December 2024 | 69 | 58.1° / 43.4° | 4.6h | 14d | 4.54" | 11 |
| January 2025 | 83 | 60.1° / 39.6° | 7.3h | 4d | 0.16" | 25 |
| February 2025 | 79 | 61.8° / 43.8° | 6.8h | 4d | 6.3" | 18 |
| March 2025 | 86 | 63.5° / 45.3° | 8.3h | 1d | 1.28" | 22 |
| April 2025 | 94 | 70.3° / 49.1° | 10.2h | 0d | 0.17" | 28 |
| May 2025 | 94 | 78.5° / 54.3° | 12.4h | 1d | 0.19" | 31 |
| June 2025 | 94 | 80.5° / 54.8° | 12.7h | 0d | 0" | 30 |
| July 2025 | 93 | 81.2° / 56.7° | 12.4h | 1d | 0" | 31 |
| August 2025 | 90 | 87.8° / 59.6° | 11.6h | 0d | 0" | 28 |
| September 2025 | 90 | 83.2° / 61.4° | 9.8h | 0d | 0.3" | 26 |
| October 2025 | 89 | 74.2° / 53.8° | 7.8h | 1d | 1.58" | 26 |
| November 2025 | 78 | 63.5° / 49.5° | 6.2h | 10d | 2.59" | 16 |
| December 2025 | 57 | 52.5° / 44.1° | 3.2h | 23d | 3.45" | 2 |
| January 2026 | 72 | 58.2° / 41.9° | 6.1h | 13d | 3.19" | 13 |
| February 2026 | 80 | 64.1° / 45.4° | 6.7h | 5d | 2.97" | 19 |
| March 2026 | 94 | 78.3° / 52.4° | 9.7h | 0d | 0" | 31 |
| April 2026 | 89 | 70° / 50.6° | 9.4h | 2d | 2.74" | 24 |
| May 2026 | 92 | 76.2° / 54.7° | 11.6h | 0d | 0.94" | 30 |
| June 2026 | 94 | 82.6° / 57.7° | 12.9h | 0d | 0" | 29 |
| July 2026 | 92 | 85.7° / 59.2° | 11.9h | 0d | 0" | 29 |
| August 2026 | 92 | 85.7° / 58.9° | 11.1h | 0d | 0" | 30 |
| September 2026 | 92 | 82.2° / 57.9° | 10h | 0d | 0.06" | 27 |
| October 2026 | 88 | 79.9° / 54.5° | 8.3h | 1d | 0.35" | 26 |
Climate Trends
Average Temperature by Month
About the Fairfield climate charts
The temperature chart compares average monthly highs and lows at Fairfield, showing both the seasonal cycle and the typical day-to-night range. The comfort chart summarizes how often the combined weather pattern is favorable rather than judging temperature alone.
Precipitation shows the total recorded or modeled rainfall for each month at Fairfield. Sunshine compares average bright-sky hours with the daylight available, while fog shows the average number of morning fog or low-cloud hours per day. Switch between the chart tabs to compare the same months across each measure.
Hourly Temperature, Fog, Wind, Cloud Cover, and Solar Radiation Patterns
Average local hour by month from 2014-09-30 to 2026-04-30
- Temperature: At Fairfield, the warmest typical hour is 4 PM in August (88°F). The coldest is 7 AM in December (42°F).
- Fog: Fog or low cloud covers Fairfield in 34% of 7 AM hours in December, the foggiest month. It thins slowly and often lasts into the early afternoon. September mornings are the least foggy (2%).
- Wind: From March through September, wind at Fairfield typically builds after 2 PM. In June it peaks around 5 PM, averaging 13 mph with 20% of those hours windy, while mornings average 9 mph.
- Cloud Cover: July middays are the clearest at Fairfield (4% average cloud cover), and December middays are the cloudiest (37%).
- Solar Radiation: The strongest typical sun at Fairfield comes at 1 PM in June, averaging 999 W/m².
How to read the hourly heatmaps for Fairfield
This heatmap shows how average temperature at Fairfield changes by hour and month. Read left to right for the seasons and top to bottom for the time of day. Warmer colors mark the usual afternoon peaks, and cooler colors show overnight and winter lows.
This heatmap shows when fog or low cloud is most likely at Fairfield. Darker cells mark the months and hours when fog has been most common. They help separate overnight or morning fog from cloud that tends to linger into the afternoon.
This heatmap shows the typical hourly wind pattern at Fairfield through the year. It makes recurring afternoon wind, calmer overnight periods, and seasonal changes easier to compare than a single daily wind value.
This heatmap shows average cloud cover at Fairfield for every month and hour. Use it to see whether cloudiness is mainly an overnight and morning pattern or commonly persists during the part of the day you plan to visit.
This heatmap shows the average solar radiation reaching Fairfield by month and hour. Brighter cells indicate the strongest typical sun, while muted cells can reflect nighttime, shorter winter days, cloud cover, smoke, or terrain shading.
Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage. The red marker shows the current month and hour.
How recent months compared at Fairfield
- October 2026 recap: October 2026 at Fairfield averaged a high of 80°F, 6°F warmer than October 2025 (74°F).
- Rain year: The 2025-26 rain year (Oct. 1 to Sep. 30) brought 17.5 in. of rain to Fairfield, 83% of the 21.1 in. normal.
Location Details
Fairfield weather questions
Everything you need to know about weather and visiting Fairfield
What is the weather like at Fairfield today?
It's 52°F at Fairfield right now, with a comfort score of 76 (great). Monday's forecast high at Fairfield is 57°F, 9°F below the mid November normal of 66°F. The best window today is 9 AM to noon, at about 53°F with a 7 mph wind (comfort 59).
What is the best month to visit Fairfield?
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Fairfield are June, September, and August. The best hours are usually 9 AM to noon in June, 9 AM to noon in September, and 9 AM to noon in August. The warm season lasts about 3 months, from Jun 25 to Sep 23, when the average high is 86°F or warmer. Highs peak around Jul 8 at about 89°F.
What are the warmest and coldest months at Fairfield?
July is the warmest month at Fairfield, with an average high of 89°F. December is the coldest, with an average low of 39°F.
When does the fog burn off at Fairfield?
Fog or low cloud covers Fairfield in 34% of 7 AM hours in December, the foggiest month. It thins slowly and often lasts into the early afternoon. September mornings are the least foggy (2%).
When is it windiest at Fairfield?
From March through September, wind at Fairfield typically builds after 2 PM. In June it peaks around 5 PM, averaging 13 mph with 20% of those hours windy, while mornings average 9 mph.
How much rain does Fairfield get?
December is the wettest month (4.4 in.), out of about 21.1 in. a year. The rainy season runs from Nov 16 to Mar 29, when a day has at least a 20% chance of measurable rain. That stretch brings 79% of the year's rain. The 2025-26 rain year (Oct. 1 to Sep. 30) brought 17.5 in. of rain to Fairfield, 83% of the 21.1 in. normal.
How does Fairfield weather compare with Vacaville?
Vacaville, 7.9 miles away, runs about 5°F warmer than Fairfield on summer afternoons.
Why is Fairfield so windy in the afternoon?
Fairfield sits just east of the Carquinez Strait, the sea-level gap that the National Weather Service lists among the main routes for marine air into the Central Valley. As the valley heats, air from San Francisco Bay pushes through the strait, bringing a sudden, gusty southwest wind in mid-afternoon on strong days. The wind usually eases around sunset.
What kind of place is Fairfield?
Fairfield spreads across the flats where Interstate 80 comes out of the southern Solano hills. It lies about 45 miles from both San Francisco and Sacramento and 15 miles from Napa Valley. Suisun City and the edge of Suisun Marsh lie immediately south, and the Suisun Valley wine district runs northwest toward Napa. Rockville Hills Regional Park covers the oak and grassland hills on the west side. Of the Solano towns in this area, it sits most directly in the path of air coming through the Carquinez Strait.
What is Fairfield weather like in November?
November at Fairfield averages a high of 66°F and a low of 44°F, with 2.2 in. of rain over about 6 rainy days. About 11% of morning hours are foggy. Afternoon wind averages 6 mph.
More about Fairfield weather
Guides that explain the weather here and nearby
Data sources and methods
- Monthly temperatures and precipitation: NOAA 1991-2020 normals.
- Fog, cloud, wind, sun, and comfort by hour and month: NOAA's HRRR hourly analysis from September 2014 to April 2026.
- Daily records and recent months: NOAA URMA and HRRR analyses, plus NOAA Stage IV precipitation.
- Nearby comparisons and regional rankings use the same hourly HRRR summaries for every destination in the region.
- Alerts: National Weather Service. Tides and ocean temperature: NOAA CO-OPS, where shown.
- All statements on this page are computed from these datasets, apart from the “What shapes the weather” guide, which cites its sources inline.
- Visit Fairfield, Rockville Hills Park (accessed 2026-10-27)
- Visit Fairfield, Discover the Wine of Suisun Valley California (accessed 2026-10-27)
- Visit Fairfield, Looping Through California Wine Country (accessed 2026-10-27)
- Bay Area Air District, Solano County community page (accessed 2026-10-27)
- Capitol Corridor, station list (accessed 2026-10-27)
- National Weather Service, Delta Breeze and stratus intrusion case study (Aug 2007) (accessed 2026-10-27)
Rendered 2026-11-15T12:16:22.215Z.