Fairfield climate

Fairfield Weather in September

NOAA 1991-2020 normals for Rosalia, 22.1 km from Fairfield

Average highs run from 81°F on September 1 to 70°F on September 30, and lows from 48°F to 40°F. Normal precipitation for the month is 0.62 in over about 4 wet days.

September day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Fairfield, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
76°F
Average low
44°F
Precipitation
0.62 in
Record high
103°FSep 2, 2025
Record low
26°FSep 23, 2000
Chance of a freeze
59%
Days of 90°F or more
2.5
Daylight
13 h 20 min to 11 h 43 min
Cloud cover
48%
Humidity
54%
Dew point
40°F
Wind
5.6 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
Sep 181°F48°F102°F 202537°F 199912%0%
Sep 281°F48°F103°F 202538°F 199912%0%
Sep 380°F47°F102°F 202541°F 199912%0%
Sep 480°F47°F97°F 202540°F 201512%0%
Sep 580°F47°F98°F 202442°F 202613%0%
Sep 679°F47°F97°F 202441°F 200113%0%
Sep 779°F46°F99°F 202438°F 199913%0%
Sep 879°F46°F94°F 201139°F 199913%0%
Sep 978°F46°F95°F 201137°F 200013%0%
Sep 1078°F46°F95°F 201143°F 200713%0%
Sep 1178°F45°F94°F 201137°F 201214%0%
Sep 1277°F45°F92°F 201135°F 201414%0%
Sep 1377°F45°F92°F 201337°F 201614%0%
Sep 1477°F44°F93°F 201338°F 201614%0%
Sep 1576°F44°F91°F 201336°F 200615%0%
Sep 1676°F44°F93°F 200937°F 201715%0%
Sep 1775°F44°F91°F 200841°F 201715%0%
Sep 1875°F43°F90°F 202540°F 201815%0%
Sep 1975°F43°F91°F 200839°F 200416%0%
Sep 2074°F43°F88°F 202538°F 200416%0%
Sep 2174°F42°F89°F 201436°F 200516%0%
Sep 2273°F42°F87°F 199931°F 200017%0%
Sep 2373°F42°F91°F 200126°F 200017%0%
Sep 2472°F42°F94°F 201132°F 200017%0%
Sep 2572°F41°F85°F 200133°F 200018%0%
Sep 2672°F41°F87°F 202236°F 199918%0%
Sep 2771°F41°F92°F 202232°F 199918%0%
Sep 2871°F40°F87°F 202530°F 199919%0%
Sep 2970°F40°F84°F 200635°F 200719%0%
Sep 3070°F40°F83°F 200835°F 199919%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Fairfield, in percent, and of at least 0.1 inch of snowfall.051015201102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PDT).

September 1
sunrise 6:08 AM, sunset 7:28 PM
September 30
sunrise 6:47 AM, sunset 6:30 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00457180 (Rosalia), public domain. Records: NOAA GHCN-Daily, station USW00094176, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.