Castaic Weather in May
Average highs run from 78°F on May 1 to 84°F on May 31, and lows from 52°F to 54°F. Normal precipitation for the month is 0.30 in over about 1 wet days.
May day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
May at a glance
- Average high
- 81°F
- Average low
- 54°F
- Precipitation
- 0.30 in
- Record high
- 98°FMay 31, 2021
- Record low
- 26°FMay 2, 1964
- Chance of a freeze
- 0%
- Days of 90°F or more
- 6.2
- Daylight
- 13 h 35 min to 14 h 18 min
- Cloud cover
- 32%
- Humidity
- 53%
- Dew point
- 42°F
- Wind
- 7.4 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 |
|---|---|---|---|---|---|---|
| May 1 | 78°F | 52°F | 85°F 1947 | 29°F 1964 | 6% | 0% |
| May 2 | 78°F | 52°F | 88°F 2017 | 26°F 1964 | 6% | 0% |
| May 3 | 78°F | 52°F | 90°F 2017 | 29°F 1950 | 6% | 0% |
| May 4 | 78°F | 52°F | 89°F 2017 | 26°F 1975 | 6% | 0% |
| May 5 | 79°F | 52°F | 87°F 2021 | 27°F 1964 | 5% | 0% |
| May 6 | 79°F | 53°F | 86°F 1990 | 29°F 1964 | 5% | 0% |
| May 7 | 79°F | 53°F | 85°F 2020 | 29°F 1964 | 5% | 0% |
| May 8 | 79°F | 53°F | 86°F 2001 | 28°F 1948 | 5% | 0% |
| May 9 | 80°F | 53°F | 86°F 1940 | 30°F 1953 | 5% | 0% |
| May 10 | 80°F | 53°F | 88°F 2026 | 31°F 2022 | 5% | 0% |
| May 11 | 80°F | 53°F | 87°F 2013 | 30°F 2010 | 4% | 0% |
| May 12 | 80°F | 53°F | 91°F 2013 | 30°F 1942 | 4% | 0% |
| May 13 | 80°F | 54°F | 91°F 2013 | 31°F 1962 | 4% | 0% |
| May 14 | 81°F | 54°F | 88°F 2022 | 28°F 1968 | 4% | 0% |
| May 15 | 81°F | 54°F | 92°F 2014 | 30°F 1984 | 4% | 0% |
| May 16 | 81°F | 54°F | 88°F 2009 | 31°F 1944 | 4% | 0% |
| May 17 | 81°F | 54°F | 89°F 2006 | 28°F 1974 | 4% | 0% |
| May 18 | 81°F | 54°F | 88°F 1954 | 29°F 1974 | 4% | 0% |
| May 19 | 82°F | 54°F | 86°F 2008 | 29°F 1974 | 4% | 0% |
| May 20 | 82°F | 54°F | 87°F 1942 | 30°F 1972 | 4% | 0% |
| May 21 | 82°F | 54°F | 88°F 2000 | 31°F 1971 | 3% | 0% |
| May 22 | 82°F | 54°F | 91°F 2017 | 31°F 1965 | 3% | 0% |
| May 23 | 82°F | 54°F | 92°F 2017 | 28°F 2010 | 3% | 0% |
| May 24 | 82°F | 54°F | 88°F 2022 | 30°F 1953 | 3% | 0% |
| May 25 | 83°F | 54°F | 94°F 1951 | 32°F 1953 | 3% | 0% |
| May 26 | 83°F | 54°F | 90°F 1974 | 30°F 1953 | 3% | 0% |
| May 27 | 83°F | 54°F | 89°F 2020 | 33°F 1953 | 3% | 0% |
| May 28 | 83°F | 54°F | 91°F 2003 | 33°F 1971 | 2% | 0% |
| May 29 | 83°F | 54°F | 92°F 1984 | 34°F 1988 | 2% | 0% |
| May 30 | 83°F | 54°F | 93°F 2021 | 33°F 1935 | 2% | 0% |
| May 31 | 84°F | 54°F | 98°F 2021 | 32°F 1967 | 2% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- May 1
- sunrise 6:04 AM, sunset 7:39 PM
- May 31
- sunrise 5:43 AM, sunset 8:01 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.