Brownsville weather in September
In September, Brownsville sees average daytime highs of 89°F and overnight lows near 75°F, with 4.2 in of rain across 15.6 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 1st-wettest month of the year here.
Highs ease over the month, from about 91°F in the first days to 87°F by the end. The sky is clear or mostly clear about 41% of the time in September, and the air most often feels oppressive.
Daylight stretches from about 12 h 30 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is Brownsville's 7th-clearest and 12th-windiest month. For the whole year in context, see Brownsville's year-round climate.
- Daytime high
- 89°
- 4th warmest
- Overnight low
- 75°
- 9th coldest
- Rainfall
- 4.2 in
- 15.6 wet days
- Daylight
- 12 h 12 min
- 6:20 AM – 6:29 PM
- Cloud cover
- 53%
- 7th clearest
- Wind
- 9 mph
- 12th windiest
- Solar energy
- 5.16 kWh/m²
- Travel score
- 3.7
- out of 10
Brownsville is seat of Cameron County, Texas, United States.
- Density
- 493/km²
- people per km²
- Founded
- 1849
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in September
Highs ease over the month, from about 91°F in the first days to 87°F by the end.
A typical September day in Brownsville reaches about 89°F in the afternoon and slips back to 75°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 84°F and 93°F. Set against its neighbours, September runs about 4°F cooler than August and about 5°F warmer than October.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 91 | 91 | 91 | 91 | 91 | 90 | 90 | 90 | 90 | 90 | 89 | 89 | 89 | 89 | 89 | 89 | 89 | 89 | 89 | 89 | 88 | 88 | 88 | 88 | 88 | 88 | 88 | 87 | 87 | 87 |
| Avg low (°F) | 77 | 77 | 77 | 77 | 77 | 77 | 77 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 75 | 75 | 75 | 75 | 75 | 74 | 74 | 74 | 74 | 74 | 73 | 73 | 73 | 73 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 91 | 77 |
| 2 | 91 | 77 |
| 3 | 91 | 77 |
| 4 | 91 | 77 |
| 5 | 91 | 77 |
| 6 | 90 | 77 |
| 7 | 90 | 77 |
| 8 | 90 | 76 |
| 9 | 90 | 76 |
| 10 | 90 | 76 |
| 11 | 89 | 76 |
| 12 | 89 | 76 |
| 13 | 89 | 76 |
| 14 | 89 | 76 |
| 15 | 89 | 76 |
| 16 | 89 | 76 |
| 17 | 89 | 75 |
| 18 | 89 | 75 |
| 19 | 89 | 75 |
| 20 | 89 | 75 |
| 21 | 88 | 75 |
| 22 | 88 | 74 |
| 23 | 88 | 74 |
| 24 | 88 | 74 |
| 25 | 88 | 74 |
| 26 | 88 | 74 |
| 27 | 88 | 73 |
| 28 | 87 | 73 |
| 29 | 87 | 73 |
| 30 | 87 | 73 |
How September really feels in Brownsville
Once humidity and wind are folded in, September averages 30 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Brownsville weather by month
How September compares with the rest of the year at a glance. September is the 4th-warmest and 1st-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 71° / 55° | 1.3 | 5.7 | 10.6 | 7.1 |
| Feb | 74° / 58° | 1.1 | 5.3 | 11.1 | 7.5 |
| Mar | 78° / 63° | 1.5 | 5.7 | 11.8 | 7.4 |
| Apr | 83° / 68° | 1.9 | 5.9 | 12.6 | 6.5 |
| May | 87° / 74° | 1.8 | 7 | 13.2 | 5.0 |
| Jun | 91° / 77° | 2.3 | 10.3 | 13.6 | 3.8 |
| Jul | 92° / 78° | 2.5 | 8.8 | 13.5 | 3.5 |
| Aug | 93° / 78° | 2.1 | 10.4 | 12.9 | 3.2 |
| Sep | 89° / 75° | 4.2 | 15.6 | 12.2 | 3.7 |
| Oct | 84° / 69° | 2.8 | 9.4 | 11.4 | 5.8 |
| Nov | 78° / 62° | 1.7 | 7.6 | 10.7 | 7.2 |
| Dec | 72° / 56° | 1.3 | 5.9 | 10.4 | 7.3 |
Cloud cover in September
The sky is clear or mostly clear about 41% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 41%. Skies tend to open up as the month goes on.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 57 | 57 | 56 | 55 | 56 | 55 | 55 | 54 | 54 | 54 | 55 | 55 | 55 | 56 | 55 | 56 | 57 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 65 | 66 | 67 | 67 |
| Cloudier (%) | 43 | 43 | 44 | 45 | 44 | 45 | 45 | 46 | 46 | 46 | 45 | 45 | 45 | 44 | 45 | 44 | 43 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 35 | 34 | 33 | 33 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 57 | 43 |
| 2 | 57 | 43 |
| 3 | 56 | 44 |
| 4 | 55 | 45 |
| 5 | 56 | 44 |
| 6 | 55 | 45 |
| 7 | 55 | 45 |
| 8 | 54 | 46 |
| 9 | 54 | 46 |
| 10 | 54 | 46 |
| 11 | 55 | 45 |
| 12 | 55 | 45 |
| 13 | 55 | 45 |
| 14 | 56 | 44 |
| 15 | 55 | 45 |
| 16 | 56 | 44 |
| 17 | 57 | 43 |
| 18 | 57 | 43 |
| 19 | 58 | 42 |
| 20 | 59 | 41 |
| 21 | 60 | 40 |
| 22 | 61 | 39 |
| 23 | 62 | 38 |
| 24 | 63 | 37 |
| 25 | 64 | 36 |
| 26 | 65 | 35 |
| 27 | 65 | 35 |
| 28 | 66 | 34 |
| 29 | 67 | 33 |
| 30 | 67 | 33 |
Chance of precipitation in September
Brownsville gets around 4.2 in of rain over 15.6 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 51% and peaks near 59% on the wettest days. The odds ease toward the end of the month.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 51 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 59 | 59 | 59 | 58 | 58 | 57 | 56 | 55 | 54 | 53 | 51 | 50 | 48 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 39 |
| Rain chance (%) | |
|---|---|
| 1 | 51 |
| 2 | 53 |
| 3 | 54 |
| 4 | 55 |
| 5 | 56 |
| 6 | 57 |
| 7 | 58 |
| 8 | 59 |
| 9 | 59 |
| 10 | 59 |
| 11 | 59 |
| 12 | 58 |
| 13 | 58 |
| 14 | 57 |
| 15 | 56 |
| 16 | 55 |
| 17 | 54 |
| 18 | 53 |
| 19 | 51 |
| 20 | 50 |
| 21 | 48 |
| 22 | 46 |
| 23 | 45 |
| 24 | 44 |
| 25 | 43 |
| 26 | 42 |
| 27 | 41 |
| 28 | 40 |
| 29 | 39 |
| 30 | 39 |
Humidity in September
Most of September feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the oppressive band about 42% of days. Sticky, muggy-or-worse air turns up on roughly 93% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Comfortable (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 3 | 3 | 3 | 4 | 4 | 4 | 5 | 5 |
| Humid (%) | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 5 | 6 | 6 | 7 | 8 | 9 | 10 | 10 | 11 | 11 | 12 | 12 | 13 |
| Muggy (%) | 4 | 4 | 4 | 4 | 5 | 5 | 5 | 5 | 5 | 6 | 6 | 6 | 7 | 7 | 8 | 8 | 9 | 9 | 10 | 10 | 11 | 12 | 13 | 13 | 14 | 15 | 15 | 16 | 17 | 17 |
| Oppressive (%) | 49 | 49 | 48 | 48 | 47 | 47 | 46 | 45 | 44 | 44 | 43 | 42 | 42 | 41 | 41 | 41 | 41 | 40 | 40 | 40 | 39 | 39 | 38 | 38 | 38 | 39 | 39 | 39 | 40 | 40 |
| Miserable (%) | 47 | 47 | 46 | 46 | 47 | 47 | 47 | 48 | 48 | 48 | 49 | 49 | 48 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 40 | 39 | 36 | 35 | 33 | 31 | 29 | 28 | 26 | 24 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| 1 | 0 | 0 | 1 | 4 | 49 | 47 |
| 2 | 0 | 0 | 1 | 4 | 49 | 47 |
| 3 | 0 | 0 | 1 | 4 | 48 | 46 |
| 4 | 0 | 0 | 1 | 4 | 48 | 46 |
| 5 | 0 | 0 | 2 | 5 | 47 | 47 |
| 6 | 0 | 0 | 2 | 5 | 47 | 47 |
| 7 | 0 | 0 | 2 | 5 | 46 | 47 |
| 8 | 0 | 0 | 2 | 5 | 45 | 48 |
| 9 | 0 | 0 | 2 | 5 | 44 | 48 |
| 10 | 0 | 0 | 2 | 6 | 44 | 48 |
| 11 | 0 | 0 | 3 | 6 | 43 | 49 |
| 12 | 0 | 0 | 3 | 6 | 42 | 49 |
| 13 | 0 | 0 | 3 | 7 | 42 | 48 |
| 14 | 0 | 0 | 3 | 7 | 41 | 48 |
| 15 | 0 | 0 | 4 | 8 | 41 | 47 |
| 16 | 0 | 1 | 4 | 8 | 41 | 46 |
| 17 | 0 | 1 | 4 | 9 | 41 | 45 |
| 18 | 0 | 1 | 5 | 9 | 40 | 44 |
| 19 | 0 | 1 | 6 | 10 | 40 | 43 |
| 20 | 0 | 2 | 6 | 10 | 40 | 42 |
| 21 | 1 | 2 | 7 | 11 | 39 | 40 |
| 22 | 1 | 2 | 8 | 12 | 39 | 39 |
| 23 | 1 | 3 | 9 | 13 | 38 | 36 |
| 24 | 1 | 3 | 10 | 13 | 38 | 35 |
| 25 | 1 | 3 | 10 | 14 | 38 | 33 |
| 26 | 1 | 4 | 11 | 15 | 39 | 31 |
| 27 | 1 | 4 | 11 | 15 | 39 | 29 |
| 28 | 1 | 4 | 12 | 16 | 39 | 28 |
| 29 | 1 | 5 | 12 | 17 | 40 | 26 |
| 30 | 1 | 5 | 13 | 17 | 40 | 24 |
Wind in September
Winds average 9 mph in September, the calmest month.
Across September, daily wind ranges from about 8 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 9 | 9 | 9 | 9 | 9 | 9 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 9 | light breeze |
| 2 | 9 | light breeze |
| 3 | 9 | light breeze |
| 4 | 9 | light breeze |
| 5 | 9 | light breeze |
| 6 | 9 | light breeze |
| 7 | 8 | light breeze |
| 8 | 8 | light breeze |
| 9 | 8 | light breeze |
| 10 | 8 | light breeze |
| 11 | 8 | light breeze |
| 12 | 8 | light breeze |
| 13 | 8 | light breeze |
| 14 | 8 | light breeze |
| 15 | 8 | light breeze |
| 16 | 9 | light breeze |
| 17 | 9 | light breeze |
| 18 | 9 | light breeze |
| 19 | 9 | light breeze |
| 20 | 9 | light breeze |
| 21 | 9 | light breeze |
| 22 | 9 | light breeze |
| 23 | 9 | light breeze |
| 24 | 9 | light breeze |
| 25 | 9 | light breeze |
| 26 | 9 | light breeze |
| 27 | 9 | light breeze |
| 28 | 9 | light breeze |
| 29 | 9 | light breeze |
| 30 | 9 | light breeze |
Sunrise & sunset in September
Daylight runs from about 12 h 30 min at the start of September to 11 h 48 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 42 minutes over September. Sunrise moves from 6:14 AM to 6:26 AM, and sunset from 6:46 PM to 6:13 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.5 | 12.5 | 12.5 | 12.5 | 12.4 | 12.4 | 12.4 | 12.4 | 12.3 | 12.3 | 12.3 | 12.3 | 12.2 | 12.2 | 12.2 | 12.2 | 12.1 | 12.1 | 12.1 | 12.0 | 12.0 | 12.0 | 12.0 | 11.9 | 11.9 | 11.9 | 11.9 | 11.8 | 11.8 | 11.8 |
| Sunrise (AM) | 6:14 | 6:14 | 6:14 | 6:15 | 6:15 | 6:16 | 6:16 | 6:17 | 6:17 | 6:17 | 6:18 | 6:18 | 6:19 | 6:19 | 6:19 | 6:20 | 6:20 | 6:21 | 6:21 | 6:21 | 6:22 | 6:22 | 6:23 | 6:23 | 6:24 | 6:24 | 6:24 | 6:25 | 6:25 | 6:26 |
| Sunset (PM) | 6:46 | 6:45 | 6:44 | 6:42 | 6:41 | 6:40 | 6:39 | 6:38 | 6:37 | 6:36 | 6:35 | 6:33 | 6:32 | 6:31 | 6:30 | 6:29 | 6:28 | 6:27 | 6:25 | 6:24 | 6:23 | 6:22 | 6:21 | 6:20 | 6:18 | 6:17 | 6:16 | 6:15 | 6:14 | 6:13 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.5 | 6:14 | 6:46 |
| 2 | 12.5 | 6:14 | 6:45 |
| 3 | 12.5 | 6:14 | 6:44 |
| 4 | 12.5 | 6:15 | 6:42 |
| 5 | 12.4 | 6:15 | 6:41 |
| 6 | 12.4 | 6:16 | 6:40 |
| 7 | 12.4 | 6:16 | 6:39 |
| 8 | 12.4 | 6:17 | 6:38 |
| 9 | 12.3 | 6:17 | 6:37 |
| 10 | 12.3 | 6:17 | 6:36 |
| 11 | 12.3 | 6:18 | 6:35 |
| 12 | 12.3 | 6:18 | 6:33 |
| 13 | 12.2 | 6:19 | 6:32 |
| 14 | 12.2 | 6:19 | 6:31 |
| 15 | 12.2 | 6:19 | 6:30 |
| 16 | 12.2 | 6:20 | 6:29 |
| 17 | 12.1 | 6:20 | 6:28 |
| 18 | 12.1 | 6:21 | 6:27 |
| 19 | 12.1 | 6:21 | 6:25 |
| 20 | 12.0 | 6:21 | 6:24 |
| 21 | 12.0 | 6:22 | 6:23 |
| 22 | 12.0 | 6:22 | 6:22 |
| 23 | 12.0 | 6:23 | 6:21 |
| 24 | 11.9 | 6:23 | 6:20 |
| 25 | 11.9 | 6:24 | 6:18 |
| 26 | 11.9 | 6:24 | 6:17 |
| 27 | 11.9 | 6:24 | 6:16 |
| 28 | 11.8 | 6:25 | 6:15 |
| 29 | 11.8 | 6:25 | 6:14 |
| 30 | 11.8 | 6:26 | 6:13 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 5.16 kWh/m².
For context, solar energy here swings from a low near 2.92 kWh/m² to a high of 6.72 kWh/m² in July across the year — September's 5.16 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.7 | 5.6 | 5.5 | 5.5 | 5.5 | 5.4 | 5.4 | 5.3 | 5.3 | 5.3 | 5.2 | 5.2 | 5.2 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 4.9 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.7 | Bright |
| 2 | 5.6 | Bright |
| 3 | 5.5 | Bright |
| 4 | 5.5 | Bright |
| 5 | 5.5 | Bright |
| 6 | 5.4 | Bright |
| 7 | 5.4 | Bright |
| 8 | 5.3 | Bright |
| 9 | 5.3 | Bright |
| 10 | 5.3 | Bright |
| 11 | 5.2 | Bright |
| 12 | 5.2 | Bright |
| 13 | 5.2 | Bright |
| 14 | 5.1 | Bright |
| 15 | 5.1 | Bright |
| 16 | 5.1 | Bright |
| 17 | 5.1 | Bright |
| 18 | 5.1 | Bright |
| 19 | 5.1 | Bright |
| 20 | 5.1 | Bright |
| 21 | 5.0 | Bright |
| 22 | 5.0 | Bright |
| 23 | 5.0 | Bright |
| 24 | 5.0 | Bright |
| 25 | 5.0 | Bright |
| 26 | 5.0 | Bright |
| 27 | 5.0 | Bright |
| 28 | 5.0 | Bright |
| 29 | 5.0 | Bright |
| 30 | 4.9 | Bright |
Hazard calendar for Brownsville
In September, Brownsville sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.
Brownsville sits in the Atlantic hurricane belt; the season peaks August–October.
Is September a good time to visit Brownsville?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is a weaker month for outdoor sightseeing in Brownsville.
What to pack for Brownsville in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Brownsville sees daytime highs around 89°F and nights near 75°F. Pack light clothes and rain gear. Worth having: sun protection. About 16 days see rain.
Sea temperature near Brownsville in September
The nearest coast averages about 84°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 23 mi away) is warmest in September at about 84°F and coldest in February near 66°F.
It's comfortable for a long swim from Mar 18 to Jan 2 — about 9.6 months when the water holds above 68°F.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 66 | 66 | 68 | 72 | 78 | 82 | 82 | 83 | 84 | 81 | 75 | 70 |
| Comfort | Cool | Cool | Cool | Refreshing | Warm | Warm | Tropical | Tropical | Tropical | Warm | Warm | Refreshing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 66 | Cool |
| Feb | 66 | Cool |
| Mar | 68 | Cool |
| Apr | 72 | Refreshing |
| May | 78 | Warm |
| Jun | 82 | Warm |
| Jul | 82 | Tropical |
| Aug | 83 | Tropical |
| Sep | 84 | Tropical |
| Oct | 81 | Warm |
| Nov | 75 | Warm |
| Dec | 70 | Refreshing |
UV index in Brownsville in September
Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Brownsville peaks around June 21 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 5 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 5 | 7 | 8 | 11 | 9 | 12 | 11 | 11 | 10 | 8 | 6 | 5 |
| Level | Moderate | High | Very high | Extreme | Very high | Extreme | Extreme | Extreme | Very high | Very high | High | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 5 | Moderate |
| Feb | 7 | High |
| Mar | 8 | Very high |
| Apr | 11 | Extreme |
| May | 9 | Very high |
| Jun | 12 | Extreme |
| Jul | 11 | Extreme |
| Aug | 11 | Extreme |
| Sep | 10 | Very high |
| Oct | 8 | Very high |
| Nov | 6 | High |
| Dec | 5 | Moderate |
Air quality in Brownsville in September
Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.
Air quality in Brownsville is worst in July — around 25 µg/m³ PM2.5 (moderate), about 3.7× the cleanest month (October, 7 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 8 | 9 | 11 | 13 | 19 | 20 | 25 | 18 | 13 | 7 | 7 | 9 |
| Level | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 8 | Good |
| Feb | 9 | Good |
| Mar | 11 | Good |
| Apr | 13 | Moderate |
| May | 19 | Moderate |
| Jun | 20 | Moderate |
| Jul | 25 | Moderate |
| Aug | 18 | Moderate |
| Sep | 13 | Moderate |
| Oct | 7 | Good |
| Nov | 7 | Good |
| Dec | 9 | Good |
Where is Brownsville?
Brownsville sits at 25.9°N, 97.5°W, 33 ft above sea level, in United States. The nearest listed city is Heroica Matamoros, 1.9 mi away.
Topography around Brownsville
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Brownsville.
Within 2 miles, the terrain around Brownsville has only modest variations in elevation — a maximum elevation change of 49 ft around an average of 36 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 92 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 259 ft.
The land around Brownsville is covered by artificial surfaces (50%) and trees (33%) within 2 miles, cropland (28%), grassland (22%) and artificial surfaces (20%) within 10 miles, and cropland (37%) and water (34%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Brownsville (25.9017°, -97.4975°, elevation 33 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).