Climate averages 1991–2020
McAllen weather
in May.
A hot, moderately wet month: the 4th warmest and the joint 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a hot month in McAllen: daytime highs average 33.0°C and nights cool to about 23.1°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 55 mm of rain on roughly 7 days, which makes May a moderately wet month (the joint 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 25 min on an average May day.
The nearest other city in this atlas is Mission (10 km away). In May its highs average 33.2°C, about as warm as McAllen, with 55 mm of rain.
Among the 498 cities listed in the United States, McAllen ranks joint 15th of 498 for the warmest May highs and joint 147th of 498 for the driest May (rainfall, lowest first). The mean May high of those 498 cities is 23.8°C; McAllen is 9.2°C warmer than that mean.
From May to June, average highs rise by 2.0°C to 34.9°C, and monthly rainfall falls from 55 mm to 51 mm.
The annual picture
May 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, selected | 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 | 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
May in nearby cities
- Mission in MayUnited States · 10 kmHigh 33.2°C · Low 23.0°C · 55 mm rain
- Edinburg in MayUnited States · 13 kmHigh 33.0°C · Low 23.1°C · 55 mm rain
- Reynosa in MayMexico · 15 kmHigh 33.2°C · Low 23.2°C · 49 mm rain
- Ciudad Río Bravo in MayMexico · 28 kmHigh 32.7°C · Low 23.2°C · 47 mm rain
- Heroica Matamoros in MayMexico · 81 kmHigh 30.1°C · Low 23.6°C · 45 mm rain
- Nuevo Laredo in MayMexico · 191 kmHigh 34.0°C · Low 22.6°C · 63 mm rain
- Corpus Christi in MayUnited States · 196 kmHigh 29.4°C · Low 22.5°C · 71 mm rain
- Ciudad Benito Juárez in MayMexico · 196 kmHigh 30.6°C · Low 19.7°C · 51 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.