Climate averages 1991–2020
McAllen weather
in September.
A hot, moderately wet month: the 5th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in McAllen: daytime highs average 32.5°C and nights cool to about 23.8°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 88 mm of rain on roughly 12 days, which makes September a moderately wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 20 min on an average September day.
The nearest other city in this atlas is Mission (10 km away). In September its highs average 32.7°C, about as warm as McAllen, with 88 mm of rain.
Among the 498 cities listed in the United States, McAllen ranks joint 23rd of 498 for the warmest September highs and joint 324th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; McAllen is 5.6°C warmer than that mean.
From September to October, average highs fall by 2.5°C to 30.1°C, and monthly rainfall falls from 88 mm to 59 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
McAllen climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 21.8°C12.1°C | 12.1°C | 26 | 4.4 | 10.711 h |
| February | 24.4°C14.1°C | 14.1°C | 24 | 4.4 | 11.311 h |
| March | 27.2°C16.8°C | 16.8°C | 36 | 5.2 | 12.012 h |
| April | 30.5°C19.9°C | 19.9°C | 44 | 5.3 | 12.813 h |
| May | 33.0°C23.1°C | 23.1°C | 55 | 6.6 | 13.413 h |
| June | 34.9°C25.1°C | 25.1°C | 51 | 7.0 | 13.714 h |
| July | 35.6°C25.5°C | 25.5°C | 55 | 5.7 | 13.614 h |
| August | 35.9°C25.7°C | 25.7°C | 39 | 6.7 | 13.113 h |
| September, selected | 32.5°C23.8°C | 23.8°C | 88 | 11.8 | 12.312 h |
| October | 30.1°C20.5°C | 20.5°C | 59 | 6.7 | 11.612 h |
| November | 25.7°C16.2°C | 16.2°C | 35 | 5.3 | 10.911 h |
| December | 22.5°C13.0°C | 13.0°C | 30 | 5.1 | 10.511 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Mission in SeptemberUnited States · 10 kmHigh 32.7°C · Low 23.8°C · 88 mm rain
- Edinburg in SeptemberUnited States · 13 kmHigh 32.6°C · Low 23.8°C · 88 mm rain
- Reynosa in SeptemberMexico · 15 kmHigh 32.7°C · Low 23.9°C · 89 mm rain
- Ciudad Río Bravo in SeptemberMexico · 28 kmHigh 32.4°C · Low 23.9°C · 94 mm rain
- Heroica Matamoros in SeptemberMexico · 81 kmHigh 30.6°C · Low 24.5°C · 108 mm rain
- Nuevo Laredo in SeptemberMexico · 191 kmHigh 33.2°C · Low 23.7°C · 77 mm rain
- Corpus Christi in SeptemberUnited States · 196 kmHigh 30.7°C · Low 23.8°C · 113 mm rain
- Ciudad Benito Juárez in SeptemberMexico · 196 kmHigh 29.2°C · Low 20.6°C · 120 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for McAllen) is explained once on the McAllen year overview and on the Sources, method and limits page.
Edinburg and Mission lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.