Castaic Weather in September
Average highs run from 95°F on September 1 to 86°F on September 30, and lows from 64°F to 59°F. Normal precipitation for the month is 0.11 in over about 1 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
- 91°F
- Average low
- 62°F
- Precipitation
- 0.11 in
- Record high
- 105°FSep 6, 2020
- Record low
- 35°FSep 25, 1948
- Chance of a freeze
- 0%
- Days of 90°F or more
- 17.2
- Daylight
- 12 h 52 min to 11 h 51 min
- Cloud cover
- 19%
- Humidity
- 36%
- Dew point
- 41°F
- Wind
- 6.0 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 | 95°F | 64°F | 99°F 2022 | 43°F 1964 | 2% | 0% |
| Sep 2 | 95°F | 64°F | 102°F 2017 | 43°F 1964 | 2% | 0% |
| Sep 3 | 95°F | 64°F | 99°F 2022 | 44°F 1936 | 2% | 0% |
| Sep 4 | 95°F | 64°F | 101°F 2020 | 43°F 1936 | 2% | 0% |
| Sep 5 | 94°F | 64°F | 102°F 2020 | 42°F 1970 | 2% | 0% |
| Sep 6 | 94°F | 64°F | 105°F 2020 | 44°F 1965 | 2% | 0% |
| Sep 7 | 94°F | 64°F | 99°F 2022 | 42°F 1965 | 2% | 0% |
| Sep 8 | 94°F | 64°F | 95°F 2018 | 46°F 1978 | 2% | 0% |
| Sep 9 | 93°F | 64°F | 98°F 1993 | 43°F 2010 | 2% | 0% |
| Sep 10 | 93°F | 64°F | 100°F 1993 | 39°F 1952 | 2% | 0% |
| Sep 11 | 93°F | 64°F | 96°F 1937 | 36°F 1952 | 2% | 0% |
| Sep 12 | 92°F | 63°F | 95°F 1971 | 39°F 1952 | 2% | 0% |
| Sep 13 | 92°F | 63°F | 95°F 1971 | 42°F 1936 | 2% | 0% |
| Sep 14 | 92°F | 63°F | 96°F 1937 | 39°F 1939 | 2% | 0% |
| Sep 15 | 91°F | 63°F | 96°F 2014 | 40°F 1959 | 2% | 0% |
| Sep 16 | 91°F | 63°F | 94°F 2000 | 41°F 1959 | 3% | 0% |
| Sep 17 | 91°F | 62°F | 93°F 2000 | 41°F 1959 | 3% | 0% |
| Sep 18 | 90°F | 62°F | 94°F 2016 | 39°F 1947 | 3% | 0% |
| Sep 19 | 90°F | 62°F | 94°F 2016 | 39°F 1965 | 3% | 0% |
| Sep 20 | 90°F | 62°F | 93°F 2015 | 37°F 1968 | 3% | 0% |
| Sep 21 | 89°F | 62°F | 90°F 1949 | 40°F 1941 | 3% | 0% |
| Sep 22 | 89°F | 61°F | 93°F 1949 | 40°F 1945 | 3% | 0% |
| Sep 23 | 88°F | 61°F | 93°F 1949 | 38°F 1986 | 3% | 0% |
| Sep 24 | 88°F | 61°F | 93°F 2015 | 38°F 1934 | 3% | 0% |
| Sep 25 | 88°F | 61°F | 91°F 1960 | 35°F 1948 | 4% | 0% |
| Sep 26 | 87°F | 60°F | 91°F 2003 | 40°F 1971 | 4% | 0% |
| Sep 27 | 87°F | 60°F | 94°F 2003 | 38°F 1971 | 4% | 0% |
| Sep 28 | 86°F | 60°F | 91°F 2022 | 40°F 1965 | 4% | 0% |
| Sep 29 | 86°F | 60°F | 90°F 2020 | 38°F 2019 | 4% | 0% |
| Sep 30 | 86°F | 59°F | 91°F 1980 | 37°F 1971 | 4% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- September 1
- sunrise 6:28 AM, sunset 7:20 PM
- September 30
- sunrise 6:49 AM, sunset 6:40 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00046161 (Newhall 5NW), public domain. Records: NOAA GHCN-Daily, station USW00023187, 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.