Brownsville Weather in September
Average highs run from 89°F on September 1 to 79°F on September 30, and lows from 60°F to 50°F. Normal precipitation for the month is 3.85 in over about 8 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
- 85°F
- Average low
- 56°F
- Precipitation
- 3.85 in
- Record high
- 105°FSep 7, 1925
- Record low
- 33°FSep 24, 1983
- Chance of a freeze
- 2%
- Days of 90°F or more
- 8.0
- Daylight
- 12 h 58 min to 11 h 50 min
- Cloud cover
- 48%
- Humidity
- 69%
- Dew point
- 58°F
- Wind
- 5.8 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 | 89°F | 60°F | 104°F 1943 | 46°F 1946 | 26% | 0% |
| Sep 2 | 89°F | 60°F | 101°F 1913 | 45°F 1987 | 26% | 0% |
| Sep 3 | 89°F | 60°F | 103°F 1913 | 48°F 1952 | 26% | 0% |
| Sep 4 | 88°F | 59°F | 103°F 1925 | 49°F 1928 | 26% | 0% |
| Sep 5 | 88°F | 59°F | 104°F 1925 | 45°F 1902 | 26% | 0% |
| Sep 6 | 88°F | 59°F | 104°F 1925 | 46°F 1988 | 26% | 0% |
| Sep 7 | 88°F | 59°F | 105°F 1925 | 43°F 1988 | 26% | 0% |
| Sep 8 | 87°F | 58°F | 103°F 1939 | 47°F 1898 | 26% | 0% |
| Sep 9 | 87°F | 58°F | 103°F 1939 | 44°F 1958 | 26% | 0% |
| Sep 10 | 87°F | 58°F | 100°F 1919 | 42°F 1924 | 26% | 0% |
| Sep 11 | 86°F | 57°F | 100°F 1912 | 40°F 1902 | 26% | 0% |
| Sep 12 | 86°F | 57°F | 98°F 1904 | 42°F 1940 | 25% | 0% |
| Sep 13 | 86°F | 57°F | 100°F 1927 | 36°F 1902 | 25% | 0% |
| Sep 14 | 85°F | 56°F | 103°F 1939 | 35°F 1902 | 25% | 0% |
| Sep 15 | 85°F | 56°F | 102°F 1927 | 39°F 1902 | 25% | 0% |
| Sep 16 | 85°F | 56°F | 101°F 1927 | 38°F 1904 | 25% | 0% |
| Sep 17 | 84°F | 55°F | 101°F 1931 | 38°F 1916 | 25% | 0% |
| Sep 18 | 84°F | 55°F | 100°F 1931 | 35°F 1903 | 26% | 0% |
| Sep 19 | 83°F | 55°F | 100°F 1925 | 36°F 1903 | 26% | 0% |
| Sep 20 | 83°F | 54°F | 98°F 1920 | 40°F 1903 | 26% | 0% |
| Sep 21 | 83°F | 54°F | 100°F 1931 | 37°F 1927 | 26% | 0% |
| Sep 22 | 82°F | 53°F | 98°F 1931 | 37°F 1913 | 26% | 0% |
| Sep 23 | 82°F | 53°F | 95°F 1931 | 37°F 1918 | 26% | 0% |
| Sep 24 | 82°F | 53°F | 95°F 1910 | 33°F 1983 | 26% | 0% |
| Sep 25 | 81°F | 52°F | 96°F 1910 | 36°F 1965 | 26% | 0% |
| Sep 26 | 81°F | 52°F | 94°F 1911 | 34°F 1928 | 26% | 0% |
| Sep 27 | 80°F | 51°F | 94°F 1923 | 35°F 1899 | 26% | 0% |
| Sep 28 | 80°F | 51°F | 95°F 1911 | 37°F 1903 | 26% | 0% |
| Sep 29 | 80°F | 51°F | 98°F 1953 | 36°F 1942 | 26% | 0% |
| Sep 30 | 79°F | 50°F | 97°F 2019 | 33°F 1949 | 26% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 6:16 AM, sunset 7:14 PM
- September 30
- sunrise 6:40 AM, sunset 6:30 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00155834 (Nolin Rvr Lake), public domain. Records: NOAA GHCN-Daily, station USW00093808, 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.