Climateby Month

Fairfield, CA climate by month

NOAA 1991-2020 normals · 14 ft elevation · also covers Vacaville

Fairfield has hot summers and cool winters. Highs peak at 90°F in July and fall to 57°F in January. The wettest month is January (about 10 wet days) and the driest is July (about 0). Snow is rare. By our comfort score the best months are April and May.

Warmest month
90°F
July normal high
Coldest month
40°F
December normal low
Wet days a year
59
24.5 in of precipitation
Muggy days a year
0
dew point 65°F or higher

How warm is Fairfield?

Normal highs range from 57°F in January to 90°F in July.

40°50°60°70°80°90° January: normal high 57°F (14°C), low 40°F (4°C) 57° 40° February: normal high 62°F (17°C), low 43°F (6°C) March: normal high 66°F (19°C), low 45°F (7°C) April: normal high 71°F (22°C), low 48°F (9°C) May: normal high 78°F (26°C), low 52°F (11°C) June: normal high 85°F (29°C), low 56°F (13°C) July: normal high 90°F (32°C), low 58°F (14°C) 90° 58° August: normal high 89°F (32°C), low 58°F (14°C) September: normal high 87°F (31°C), low 57°F (14°C) October: normal high 78°F (26°C), low 52°F (11°C) November: normal high 66°F (19°C), low 45°F (7°C) December: normal high 57°F (14°C), low 40°F (4°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Fairfield?

January has the most wet days (about 10); the year brings about 25 in of precipitation.

January: 10 wet days 10 February: 10 wet days March: 9 wet days April: 5 wet days May: 3 wet days June: 1 wet days July: 0 wet days 0 August: 0 wet days September: 1 wet days October: 3 wet days November: 7 wet days December: 10 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How humid is Fairfield?

Muggy days (dew point 65°F or higher) are rare in any month.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 0 muggy days June: 0 muggy days July: 0 muggy days August: 0 muggy days September: 0 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Travis Air Force Base, 5.9 mi ENE of the city center.

How much daylight?

Daylight ranges from about 9.6 hours in December to 14.8 hours in June.

January: 9.8 hours of daylight February: 10.8 hours of daylight March: 12.0 hours of daylight April: 13.2 hours of daylight May: 14.3 hours of daylight June: 14.8 hours of daylight 14.8 July: 14.5 hours of daylight August: 13.6 hours of daylight September: 12.4 hours of daylight October: 11.2 hours of daylight November: 10.1 hours of daylight December: 9.6 hours of daylight 9.6 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Fairfield, 1991-2020
MonthHighLowPrecip.Wet daysMuggy daysDaylight
January 57°F40°F 4.7 in10 0 9.8 h
February 62°F43°F 5.0 in10 0 10.8 h
March 66°F45°F 3.3 in9 0 12.0 h
April 71°F48°F 1.5 in5 0 13.2 h
May 78°F52°F 0.7 in3 0 14.3 h
June 85°F56°F 0.2 in1 0 14.8 h
July 90°F58°F 0.0 in0 0 14.5 h
August 89°F58°F 0.03 in0 0 13.6 h
September 87°F57°F 0.08 in1 0 12.4 h
October 78°F52°F 1.1 in3 0 11.2 h
November 66°F45°F 2.5 in7 0 10.1 h
December 57°F40°F 5.4 in10 0 9.6 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Fairfield

By our comfort score, the best months are April and May.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 46480
Feb 571080
Mar 681770
Apr 771931
May 791924
Jun 6610110
Jul 544015
Aug 524015
Sep 536012
Oct 691723
Nov 651650
Dec 44380

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Fairfield

The last spring frost typically comes around Jan 15, and the first fall frost around Dec 14, leaving 336 frost-free days in a typical year.

Frost and freeze dates for Fairfield
Typical date1 year in 10
Last spring frost (32°F)Jan 15after Feb 16
First fall frost (32°F)Dec 14before Nov 29
Hard freeze (28°F)in about 44% of years; no typical date
Frost-free season336 daysunder 296 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Fairfield (USC00042934), NOAA 1991-2020 freeze probabilities. Frost dates for every city in California.

Hottest and coldest readings, 1991-2020

The highest reading was 114°F (July 24, 2006); the lowest was 15°F (December 25, 2011).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Fairfield

Similar climates elsewhere

Also covers

Vacaville uses the same temperature and rain stations as Fairfield, so its monthly numbers are the ones on this page.

Where the numbers come from

  • Temperature, rain, snowfall, snow depth and frost dates: Fairfield (USC00042934), 2.3 mi NW of the city center, 40 ft . NOAA normals and daily records, 1991-2020.
  • Humidity and wind by hour and cloud cover: Travis AFB (USW00023202), 5.9 mi ENE of the city center, 59 ft . NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Travis Air Force Base (745160-23202), 5.9 mi ENE of the city center, 62 ft . Hourly observations, 1991-2020.

Distances from the city center (USGS). Methodology · Report an error