Lake County climate

Lake County Weather in September

NOAA 1991-2020 normals for Clearlake 4 Se, 25.3 km from Lake County

Average highs run from 89°F on September 1 to 81°F on September 30, and lows from 52°F to 48°F. Normal precipitation for the month is 0.17 in over about 1 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 Lake County, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
85°F
Average low
50°F
Precipitation
0.17 in
Record high
117°FSep 6, 2022
Record low
38°FSep 26, 2013
Chance of a freeze
0%
Days of 90°F or more
13.4
Daylight
13 h 01 min to 11 h 49 min
Cloud cover
17%
Humidity
45%
Dew point
42°F
Wind
4.7 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 189°F52°F109°F 201744°F 20082%0%
Sep 288°F52°F111°F 201746°F 20082%0%
Sep 388°F52°F108°F 201748°F 20042%0%
Sep 488°F52°F105°F 202447°F 20022%0%
Sep 588°F52°F112°F 202244°F 20152%0%
Sep 688°F52°F117°F 202245°F 20022%0%
Sep 788°F52°F111°F 202043°F 20022%0%
Sep 887°F52°F110°F 202244°F 20022%0%
Sep 987°F51°F109°F 202245°F 20122%0%
Sep 1087°F51°F105°F 201546°F 20052%0%
Sep 1187°F51°F104°F 201544°F 20052%0%
Sep 1287°F51°F103°F 200644°F 19492%0%
Sep 1386°F51°F102°F 200644°F 20052%0%
Sep 1486°F51°F102°F 202143°F 20052%0%
Sep 1586°F51°F95°F 200842°F 20172%0%
Sep 1686°F50°F95°F 201640°F 20062%0%
Sep 1785°F50°F98°F 201645°F 19493%0%
Sep 1885°F50°F100°F 194945°F 19493%0%
Sep 1985°F50°F100°F 200242°F 20083%0%
Sep 2085°F50°F103°F 194941°F 20043%0%
Sep 2184°F50°F104°F 200341°F 20173%0%
Sep 2284°F49°F105°F 200340°F 20173%0%
Sep 2384°F49°F103°F 200940°F 20174%0%
Sep 2483°F49°F103°F 201940°F 20054%0%
Sep 2583°F49°F104°F 200939°F 20054%0%
Sep 2683°F49°F109°F 200938°F 20134%0%
Sep 2782°F48°F107°F 200940°F 20134%0%
Sep 2882°F48°F103°F 201044°F 20135%0%
Sep 2982°F48°F104°F 201039°F 20075%0%
Sep 3081°F48°F102°F 202039°F 20075%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Lake County, in percent, and of at least 0.1 inch of snowfall.02461102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PDT).

September 1
sunrise 6:40 AM, sunset 7:41 PM
September 30
sunrise 7:06 AM, sunset 6:55 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00041806 (Clearlake 4 Se), public domain. Records: NOAA GHCN-Daily, station USW00023275, 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.