Port Isabel, TX climate
Port Isabel has warm winters and warm summers. A typical July afternoon reaches 92°, a January night drops to 52°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Port Isabel feels like
Winter
Spring
Summer
Fall
Port Isabel weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 70° | 52° | 1.2" | 0 | 8 | 0 | 55° – 67° |
| February | 73° | 57° | 1.1" | 0 | 5 | 0 | 58° – 73° |
| March | 77° | 62° | 1.4" | 0 | 5 | 0 | 63° – 76° |
| April | 82° | 67° | 1.4" | 0 | 4 | 0 | 70° – 79° |
| May | 87° | 73° | 2.2" | 0 | 4 | 0 | 76° – 83° |
| June | 91° | 77° | 3.0" | 0 | 4 | 0 | 81° – 87° |
| July | 92° | 77° | 1.8" | 0 | 4 | 0 | 82° – 87° |
| August | 93° | 77° | 2.0" | 0 | 4 | 0 | 83° – 88° |
| September | 90° | 74° | 5.4" | 0 | 8 | 0 | 79° – 85° |
| October | 85° | 68° | 3.3" | 0 | 7 | 0 | 74° – 80° |
| November | 78° | 61° | 1.9" | 0 | 6 | 0 | 64° – 75° |
| December | 72° | 54° | 1.4" | 0.2" | 8 | 0 | 57° – 67° |
| Year | 82° | 67° | 26.1" | 0.2" | 67 | 0 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Port Isabel
Port Isabel gets 26 inches of rain and melted snow a year. September is the wettest month and February the driest. Rain or snow falls on about 67 days a year.
A year-round growing season
Heating and cooling a home in Port Isabel
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Port Isabel, 13% of that work is heating and 87% is cooling, so air conditioning is the bigger bill.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Port Isabel and its neighbors
Port Isabel borders 2 towns with climate data. January nights across them vary by 1.2°. Brownsville has both the coldest January nights (52°) and the hottest July afternoons (94°). Port Isabel’s January low is 52° and its July high 92°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Port Isabel compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Port Isabel averaged 1.2° warmer than the 1900s. The biggest change is in February (+2.3°). The shift is smaller than in 51% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Port Isabel’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 58° to 73°. June is the most reliable, staying within 5°.
Common questions about Port Isabel’s climate
What is the coldest month in Port Isabel?
January, with a typical high of 70° and a low of 52°.
What is the hottest month in Port Isabel?
August, with a typical high of 93° and a low of 77°. About 95 days a year reach 90°.
How much snow does Port Isabel get?
Almost none. A normal year brings 0.2 inches.
When is the first frost in Port Isabel?
Frost is uncommon. Only 34% of years see a night at 32° or below.
What is the rainiest month in Port Isabel?
September, with 5.4 inches of rain and melted snow. The year totals 26 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Port Isabel itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Port Isabel, TX (2 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.