Brownsville Weather in September
Average highs run from 80°F on September 1 to 71°F on September 30, and lows from 49°F to 45°F. Normal precipitation for the month is 1.99 in over about 7 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
- 76°F
- Average low
- 47°F
- Precipitation
- 1.99 in
- Record high
- 95°FSep 3, 2017
- Record low
- 34°FSep 29, 2019
- Chance of a freeze
- 5%
- Days of 90°F or more
- 2.3
- Daylight
- 13 h 13 min to 11 h 45 min
- Cloud cover
- 42%
- Humidity
- 75%
- Dew point
- 51°F
- Wind
- 5.1 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 |
|---|---|---|---|---|---|---|
| Sep 1 | 80°F | 49°F | 93°F 2017 | 39°F 2008 | 16% | 0% |
| Sep 2 | 80°F | 49°F | 94°F 2017 | 41°F 2012 | 17% | 0% |
| Sep 3 | 80°F | 48°F | 95°F 2017 | 41°F 2008 | 17% | 0% |
| Sep 4 | 80°F | 48°F | 93°F 2025 | 41°F 2015 | 18% | 0% |
| Sep 5 | 80°F | 48°F | 93°F 2014 | 39°F 2015 | 18% | 0% |
| Sep 6 | 79°F | 48°F | 95°F 2014 | 41°F 2010 | 19% | 0% |
| Sep 7 | 79°F | 48°F | 93°F 2012 | 42°F 2018 | 19% | 0% |
| Sep 8 | 79°F | 48°F | 89°F 2021 | 40°F 2022 | 20% | 0% |
| Sep 9 | 79°F | 48°F | 91°F 2011 | 43°F 2018 | 20% | 0% |
| Sep 10 | 78°F | 48°F | 94°F 2007 | 39°F 2008 | 20% | 0% |
| Sep 11 | 78°F | 48°F | 91°F 2015 | 42°F 2026 | 21% | 0% |
| Sep 12 | 78°F | 47°F | 91°F 2017 | 41°F 2016 | 21% | 0% |
| Sep 13 | 78°F | 47°F | 88°F 2012 | 42°F 2008 | 22% | 0% |
| Sep 14 | 77°F | 47°F | 89°F 2014 | 40°F 2016 | 22% | 0% |
| Sep 15 | 77°F | 47°F | 91°F 2023 | 40°F 2018 | 23% | 0% |
| Sep 16 | 77°F | 47°F | 91°F 2025 | 42°F 2021 | 24% | 0% |
| Sep 17 | 76°F | 47°F | 87°F 2012 | 42°F 2021 | 24% | 0% |
| Sep 18 | 76°F | 47°F | 83°F 2009 | 40°F 2018 | 25% | 0% |
| Sep 19 | 76°F | 46°F | 83°F 2014 | 38°F 2018 | 25% | 0% |
| Sep 20 | 75°F | 46°F | 90°F 2014 | 40°F 2009 | 26% | 0% |
| Sep 21 | 75°F | 46°F | 87°F 2009 | 39°F 2017 | 26% | 0% |
| Sep 22 | 75°F | 46°F | 89°F 2009 | 40°F 2006 | 27% | 0% |
| Sep 23 | 74°F | 46°F | 87°F 2025 | 37°F 2007 | 27% | 0% |
| Sep 24 | 74°F | 46°F | 88°F 2025 | 36°F 2007 | 28% | 0% |
| Sep 25 | 73°F | 46°F | 85°F 2022 | 39°F 2007 | 28% | 0% |
| Sep 26 | 73°F | 45°F | 90°F 2016 | 39°F 2008 | 29% | 0% |
| Sep 27 | 73°F | 45°F | 86°F 2017 | 40°F 2013 | 29% | 0% |
| Sep 28 | 72°F | 45°F | 86°F 2017 | 38°F 2015 | 30% | 0% |
| Sep 29 | 72°F | 45°F | 83°F 2006 | 34°F 2019 | 31% | 0% |
| Sep 30 | 71°F | 45°F | 80°F 2010 | 36°F 2019 | 31% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- September 1
- sunrise 6:35 AM, sunset 7:48 PM
- September 30
- sunrise 7:09 AM, sunset 6:54 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00353047 (Foster Dam), public domain. Records: NOAA GHCN-Daily, station USW00004236, 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.