Arnold Weather in September
Average highs run from 77°F on September 1 to 69°F on September 30, and lows from 53°F to 47°F. Normal precipitation for the month is 0.39 in over about 2 wet days.
September day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 74°F
- Average low
- 51°F
- Precipitation
- 0.39 in
- Record high
- 110°FSep 7, 2022
- Record low
- 33°FSep 18, 2026
- Chance of a freeze
- 6%
- Daylight
- 13 h 00 min to 11 h 50 min
- Cloud cover
- 20%
- Humidity
- 34%
- Dew point
- 35°F
- Wind
- 5.8 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.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Sep 1 | 77°F | 53°F | 108°F 1955 | 41°F 1964 | 4% | 0% |
| Sep 2 | 77°F | 53°F | 105°F 1969 | 40°F 1964 | 4% | 0% |
| Sep 3 | 77°F | 53°F | 108°F 1955 | 45°F 1964 | 4% | 0% |
| Sep 4 | 77°F | 53°F | 104°F 1988 | 44°F 2000 | 5% | 0% |
| Sep 5 | 77°F | 53°F | 107°F 1950 | 42°F 1970 | 5% | 0% |
| Sep 6 | 76°F | 53°F | 108°F 2022 | 43°F 2000 | 5% | 0% |
| Sep 7 | 76°F | 52°F | 110°F 2022 | 42°F 1978 | 5% | 0% |
| Sep 8 | 76°F | 52°F | 105°F 1944 | 39°F 1983 | 5% | 0% |
| Sep 9 | 76°F | 52°F | 106°F 1944 | 38°F 1985 | 5% | 0% |
| Sep 10 | 75°F | 52°F | 102°F 1948 | 38°F 1985 | 5% | 0% |
| Sep 11 | 75°F | 52°F | 104°F 1944 | 37°F 1985 | 6% | 0% |
| Sep 12 | 75°F | 52°F | 104°F 1979 | 35°F 1985 | 6% | 0% |
| Sep 13 | 75°F | 51°F | 104°F 1945 | 39°F 1966 | 6% | 0% |
| Sep 14 | 74°F | 51°F | 105°F 1971 | 38°F 1986 | 6% | |
| Sep 15 | 74°F | 51°F | 106°F 1971 | 36°F 1986 | 6% | |
| Sep 16 | 74°F | 51°F | 105°F 1971 | 34°F 2026 | 6% | |
| Sep 17 | 74°F | 51°F | 102°F 1971 | 34°F 2026 | 6% | |
| Sep 18 | 73°F | 50°F | 103°F 1984 | 33°F 2026 | 7% | |
| Sep 19 | 73°F | 50°F | 100°F 1939 | 37°F 1965 | 7% | |
| Sep 20 | 73°F | 50°F | 102°F 1939 | 38°F 1970 | 7% | |
| Sep 21 | 72°F | 50°F | 100°F 1939 | 38°F 2004 | 7% | |
| Sep 22 | 72°F | 49°F | 101°F 1949 | 37°F 2016 | 7% | |
| Sep 23 | 72°F | 49°F | 104°F 1949 | 37°F 2017 | 7% | |
| Sep 24 | 71°F | 49°F | 100°F 1949 | 36°F 1920 | 7% | |
| Sep 25 | 71°F | 49°F | 100°F 1962 | 35°F 1920 | 7% | |
| Sep 26 | 71°F | 48°F | 100°F 1963 | 37°F 2013 | 8% | |
| Sep 27 | 70°F | 48°F | 104°F 1963 | 36°F 1948 | 8% | |
| Sep 28 | 70°F | 48°F | 102°F 1963 | 37°F 1971 | 8% | |
| Sep 29 | 70°F | 47°F | 102°F 2010 | 36°F 1982 | 8% | |
| Sep 30 | 69°F | 47°F | 98°F 1991 | 36°F 1950 | 8% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- September 1
- sunrise 6:31 AM, sunset 7:31 PM
- September 30
- sunrise 6:56 AM, sunset 6:46 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00041277 (Calaveras Big Trees), public domain. Records: NOAA GHCN-Daily, station USC00048353, 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.