San Ramon Weather in May
Average highs run from 65°F on May 1 to 71°F on May 31, and lows from 47°F to 52°F. Normal precipitation for the month is 1.13 in over about 4 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
- 68°F
- Average low
- 49°F
- Precipitation
- 1.13 in
- Record high
- 108°FMay 30, 1910
- Record low
- 32°FMay 4, 1952
- Chance of a freeze
- 1%
- Days of 90°F or more
- 0.8
- Daylight
- 13 h 47 min to 14 h 36 min
- Cloud cover
- 35%
- Humidity
- 69%
- Dew point
- 48°F
- Wind
- 10.1 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 | 65°F | 47°F | 96°F 1947 | 35°F 1965 | 18% | 0% |
| May 2 | 65°F | 47°F | 95°F 2004 | 33°F 1965 | 18% | 0% |
| May 3 | 65°F | 47°F | 94°F 2004 | 33°F 1968 | 17% | 0% |
| May 4 | 65°F | 47°F | 96°F 1990 | 32°F 1952 | 17% | 0% |
| May 5 | 66°F | 47°F | 97°F 1987 | 32°F 1952 | 17% | 0% |
| May 6 | 66°F | 48°F | 101°F 1987 | 34°F 1965 | 16% | 0% |
| May 7 | 66°F | 48°F | 101°F 1987 | 32°F 1916 | 16% | 0% |
| May 8 | 66°F | 48°F | 98°F 2001 | 35°F 1930 | 16% | 0% |
| May 9 | 66°F | 48°F | 97°F 1931 | 36°F 1916 | 15% | 0% |
| May 10 | 67°F | 48°F | 99°F 1934 | 35°F 1968 | 15% | 0% |
| May 11 | 67°F | 49°F | 101°F 1934 | 37°F 1922 | 15% | 0% |
| May 12 | 67°F | 49°F | 100°F 1976 | 37°F 1909 | 15% | 0% |
| May 13 | 67°F | 49°F | 99°F 1972 | 36°F 1943 | 14% | 0% |
| May 14 | 67°F | 49°F | 98°F 1972 | 34°F 1964 | 14% | 0% |
| May 15 | 68°F | 49°F | 98°F 1970 | 34°F 1908 | 14% | 0% |
| May 16 | 68°F | 49°F | 101°F 1970 | 34°F 1908 | 14% | 0% |
| May 17 | 68°F | 50°F | 103°F 2009 | 35°F 1917 | 13% | 0% |
| May 18 | 68°F | 50°F | 97°F 1973 | 36°F 1974 | 13% | 0% |
| May 19 | 68°F | 50°F | 97°F 1952 | 38°F 1939 | 13% | 0% |
| May 20 | 69°F | 50°F | 99°F 2001 | 38°F 1922 | 13% | 0% |
| May 21 | 69°F | 50°F | 100°F 2000 | 37°F 1927 | 12% | 0% |
| May 22 | 69°F | 50°F | 99°F 2000 | 38°F 1960 | 12% | 0% |
| May 23 | 69°F | 51°F | 101°F 1943 | 39°F 1917 | 12% | 0% |
| May 24 | 70°F | 51°F | 102°F 2022 | 39°F 1909 | 11% | 0% |
| May 25 | 70°F | 51°F | 102°F 2022 | 35°F 1910 | 11% | 0% |
| May 26 | 70°F | 51°F | 103°F 1951 | 37°F 1953 | 11% | 0% |
| May 27 | 70°F | 51°F | 102°F 1951 | 38°F 1953 | 10% | 0% |
| May 28 | 70°F | 51°F | 103°F 1984 | 41°F 1953 | 10% | 0% |
| May 29 | 71°F | 52°F | 105°F 1910 | 40°F 1918 | 9% | 0% |
| May 30 | 71°F | 52°F | 108°F 1910 | 40°F 1917 | 9% | 0% |
| May 31 | 71°F | 52°F | 104°F 1910 | 41°F 1908 | 9% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- May 1
- sunrise 6:12 AM, sunset 7:59 PM
- May 31
- sunrise 5:48 AM, sunset 8:24 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00045915 (Mt Diablo Junction), public domain. Records: NOAA GHCN-Daily, station USC00044997, 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.