Rio Vista Weather in September
Average highs run from 92°F on September 1 to 84°F on September 30, and lows from 70°F to 61°F. Normal precipitation for the month is 3.02 in over about 5 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
- 89°F
- Average low
- 66°F
- Precipitation
- 3.02 in
- Record high
- 114°FSep 2, 1939
- Record low
- 30°FSep 27, 1908
- Chance of a freeze
- 0%
- Days of 90°F or more
- 16.8
- Daylight
- 12 h 49 min to 11 h 52 min
- Cloud cover
- 41%
- Humidity
- 63%
- Dew point
- 62°F
- Wind
- 8.3 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 | 92°F | 70°F | 112°F 1939 | 54°F 1915 | 17% | 0% |
| Sep 2 | 92°F | 70°F | 114°F 1939 | 53°F 1915 | 17% | 0% |
| Sep 3 | 92°F | 70°F | 110°F 1939 | 57°F 1974 | 17% | 0% |
| Sep 4 | 92°F | 69°F | 111°F 2000 | 51°F 1974 | 17% | 0% |
| Sep 5 | 91°F | 69°F | 108°F 1963 | 50°F 1974 | 17% | 0% |
| Sep 6 | 91°F | 69°F | 108°F 1963 | 49°F 1974 | 17% | 0% |
| Sep 7 | 91°F | 69°F | 106°F 1963 | 50°F 1974 | 17% | 0% |
| Sep 8 | 91°F | 68°F | 107°F 2023 | 52°F 1918 | 17% | 0% |
| Sep 9 | 90°F | 68°F | 104°F 1931 | 53°F 2004 | 17% | 0% |
| Sep 10 | 90°F | 68°F | 109°F 2023 | 53°F 1929 | 17% | 0% |
| Sep 11 | 90°F | 67°F | 102°F 1930 | 50°F 1968 | 17% | 0% |
| Sep 12 | 90°F | 67°F | 103°F 1926 | 47°F 1940 | 17% | 0% |
| Sep 13 | 89°F | 67°F | 103°F 1926 | 50°F 1940 | 17% | 0% |
| Sep 14 | 89°F | 66°F | 106°F 2011 | 49°F 1945 | 17% | 0% |
| Sep 15 | 89°F | 66°F | 106°F 2011 | 47°F 1945 | 17% | 0% |
| Sep 16 | 89°F | 66°F | 103°F 1968 | 50°F 1945 | 17% | 0% |
| Sep 17 | 88°F | 65°F | 102°F 1931 | 49°F 1951 | 16% | 0% |
| Sep 18 | 88°F | 65°F | 101°F 1980 | 45°F 1981 | 16% | 0% |
| Sep 19 | 88°F | 65°F | 101°F 1956 | 42°F 1981 | 16% | 0% |
| Sep 20 | 88°F | 64°F | 102°F 1953 | 43°F 1971 | 16% | 0% |
| Sep 21 | 87°F | 64°F | 100°F 1956 | 44°F 1913 | 16% | 0% |
| Sep 22 | 87°F | 64°F | 99°F 1925 | 40°F 1983 | 16% | 0% |
| Sep 23 | 87°F | 63°F | 101°F 2005 | 44°F 1994 | 16% | 0% |
| Sep 24 | 86°F | 63°F | 101°F 1907 | 48°F 1914 | 16% | 0% |
| Sep 25 | 86°F | 63°F | 103°F 1931 | 42°F 1989 | 16% | 0% |
| Sep 26 | 86°F | 62°F | 104°F 1977 | 41°F 2000 | 16% | 0% |
| Sep 27 | 85°F | 62°F | 107°F 1977 | 30°F 1908 | 16% | 0% |
| Sep 28 | 85°F | 61°F | 107°F 1953 | 38°F 1908 | 16% | 0% |
| Sep 29 | 85°F | 61°F | 105°F 2005 | 39°F 1908 | 16% | 0% |
| Sep 30 | 84°F | 61°F | 101°F 1977 | 40°F 1984 | 16% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 7:05 AM, sunset 7:54 PM
- September 30
- sunrise 7:23 AM, sunset 7:15 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00411800 (Cleburne), public domain. Records: NOAA GHCN-Daily, station USC00411800, 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.