Rio Weather in September
Average highs run from 90°F on September 1 to 88°F on September 30, and lows from 76°F to 75°F. Normal precipitation for the month is 8.28 in over about 16 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
- 75°F
- Precipitation
- 8.28 in
- Record high
- 102°FSep 6, 1992
- Record low
- 58°FSep 29, 2008
- Chance of a freeze
- 0%
- Days of 90°F or more
- 13.1
- Daylight
- 12 h 41 min to 11 h 55 min
- Cloud cover
- 62%
- Humidity
- 81%
- Dew point
- 75°F
- Wind
- 8.9 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Sep 1 | 90°F | 76°F | 96°F 1944 | 67°F 1975 | 53% |
| Sep 2 | 90°F | 76°F | 95°F 1944 | 69°F 1951 | 53% |
| Sep 3 | 90°F | 76°F | 96°F 1944 | 68°F 1970 | 53% |
| Sep 4 | 90°F | 76°F | 97°F 1999 | 69°F 1967 | 54% |
| Sep 5 | 90°F | 76°F | 96°F 1996 | 68°F 1972 | 54% |
| Sep 6 | 90°F | 76°F | 102°F 1992 | 68°F 1974 | 54% |
| Sep 7 | 90°F | 76°F | 96°F 1962 | 68°F 1965 | 54% |
| Sep 8 | 89°F | 76°F | 96°F 1944 | 66°F 1968 | 54% |
| Sep 9 | 89°F | 76°F | 96°F 1937 | 67°F 1970 | 54% |
| Sep 10 | 89°F | 75°F | 96°F 1973 | 65°F 1972 | 54% |
| Sep 11 | 89°F | 75°F | 97°F 1951 | 67°F 1972 | 54% |
| Sep 12 | 89°F | 75°F | 96°F 1950 | 67°F 1972 | 54% |
| Sep 13 | 89°F | 75°F | 97°F 1950 | 68°F 1972 | 54% |
| Sep 14 | 89°F | 75°F | 95°F 1944 | 66°F 1968 | 54% |
| Sep 15 | 89°F | 75°F | 95°F 1951 | 65°F 1939 | 53% |
| Sep 16 | 89°F | 75°F | 97°F 1950 | 68°F 1962 | 53% |
| Sep 17 | 89°F | 75°F | 97°F 1951 | 69°F 1937 | 53% |
| Sep 18 | 89°F | 75°F | 98°F 1946 | 68°F 1985 | 53% |
| Sep 19 | 89°F | 75°F | 96°F 1987 | 68°F 1981 | 53% |
| Sep 20 | 89°F | 75°F | 97°F 1937 | 69°F 1976 | 53% |
| Sep 21 | 88°F | 75°F | 96°F 1937 | 66°F 1938 | 53% |
| Sep 22 | 88°F | 75°F | 97°F 1998 | 69°F 1938 | 53% |
| Sep 23 | 88°F | 75°F | 95°F 1950 | 66°F 1966 | 53% |
| Sep 24 | 88°F | 75°F | 94°F 1967 | 65°F 2008 | 53% |
| Sep 25 | 88°F | 75°F | 92°F 1939 | 68°F 1990 | 53% |
| Sep 26 | 88°F | 75°F | 93°F 1944 | 66°F 1967 | 53% |
| Sep 27 | 88°F | 75°F | 95°F 1939 | 62°F 1956 | 53% |
| Sep 28 | 88°F | 75°F | 95°F 1942 | 65°F 2008 | 53% |
| Sep 29 | 88°F | 75°F | 97°F 1974 | 58°F 2008 | 52% |
| Sep 30 | 88°F | 75°F | 95°F 1974 | 64°F 2022 | 52% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (EDT).
- September 1
- sunrise 7:00 AM, sunset 7:41 PM
- September 30
- sunrise 7:13 AM, sunset 7:08 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00088620 (Stuart), public domain. Records: NOAA GHCN-Daily, station USC00088620, 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.