August is one of the warmer months of the year in Mcallen, with average highs near 35.8°C and lows around 25.2°C (mean 30.5°C). It is about average for rainfall, averaging 52 mm of rainfall and 67% relative humidity across the period.
August is one of the warmer months of the year in Mcallen. Across 45 years of records, the warmest August in Mcallen was 2023 — when the month averaged 32.7°C — while the coldest was 2008 at 29°C. Typical August days reach 35.8°C with nights near 25.2°C. The long-term trend is warming, about 0.3°C per decade.
August is about average for rainfall in Mcallen, averaging 52 mm of rainfall. The wettest August on record was 1981 with 170 mm, while the driest was 1993 at 3 mm.
Relative humidity in Mcallen during August averages 67%. The most humid August was 2008 at 77%, and the least humid was 2009 at 60%.
August receives about 6.5 kWh/m²/day of solar energy in Mcallen. The sunniest Augusts were 2011 and 2019 at 7 kWh/m²/day, and the cloudiest was 2008 at 5.7.
Average wind speed in Mcallen during August is 3.3 m/s. The windiest Augusts were 1993, 2001 and 2019 at 3.9 m/s, while the calmest were 1995 and 2024 at 2.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 29.9°C | 30.2°C | 30.3°C | 31.2°C | 31.0°C | +1.1°C |
| Avg High | 35.2°C | 35.5°C | 35.4°C | 36.7°C | 36.4°C | +1.2°C |
| Avg Low | 24.7°C | 25.0°C | 25.2°C | 25.5°C | 25.6°C | +0.9°C |
| Avg Rain | 67 mm | 63 mm | 56 mm | 30 mm | 41 mm | -26 mm |
August temperatures in Mcallen have risen by about 1.1°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 21.3°C (1992) to a record high of 42.6°C (2023).
Rainfall in August is about average for rainfall, averaging 52 mm, with a wettest year of 170 mm.
A quieter season to visit Mcallen
If your dates are flexible, the more temperate months of March and November tend to be the most comfortable for visiting Mcallen. That said, August — with days averaging 35.8°C and nights around 25.2°C (mean 30.5°C) and moderate rainfall (52 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 36.3°C | 30.8°C | 25.4°C | 39.6°C | 24.5°C | 59 mm | 68% | 2.9 m/s | 6.7 |
| 2024 | 36.8°C | 31.4°C | 25.9°C | 39.7°C | 24.0°C | 38 mm | 67% | 2.5 m/s | 6.7 |
| 2023 🔥 | 38.8°C | 32.7°C | 26.5°C | 42.6°C | 23.6°C | 32 mm | 62% | 3.6 m/s | 6.9 |
| 2022 | 35.4°C | 30.5°C | 25.6°C | 39.1°C | 24.7°C | 84 mm | 69% | 3.5 m/s | 6.2 |
| 2021 | 34.6°C | 29.8°C | 25.0°C | 37.6°C | 23.8°C | 18 mm | 73% | 3.1 m/s | 6.9 |
| 2020 | 36.6°C | 30.9°C | 25.3°C | 39.5°C | 23.2°C | 17 mm | 66% | 3.2 m/s | 6.9 |
| 2019 | 38.1°C | 32.2°C | 26.4°C | 40.5°C | 24.4°C | 12 mm | 63% | 3.9 m/s | 7 |
| 2018 | 36.1°C | 30.7°C | 25.3°C | 38.8°C | 24.0°C | 16 mm | 65% | 3.7 m/s | 6.9 |
| 2017 | 36.9°C | 31.4°C | 25.9°C | 39.6°C | 24.5°C | 47 mm | 64% | 3.7 m/s | 6.4 |
| 2016 | 36.5°C | 31.2°C | 26.0°C | 39.4°C | 24.9°C | 35 mm | 65% | 3.4 m/s | 6.4 |
| 2015 | 36.5°C | 30.9°C | 25.2°C | 39.8°C | 21.8°C | 74 mm | 65% | 3.4 m/s | 6.9 |
| 2014 | 36.4°C | 31.0°C | 25.6°C | 39.7°C | 24.2°C | 39 mm | 64% | 3.6 m/s | 6.5 |
| 2013 | 36.6°C | 30.8°C | 24.9°C | 40.2°C | 23.4°C | 38 mm | 64% | 3.3 m/s | 6.4 |
| 2012 | 37.4°C | 31.5°C | 25.5°C | 41.1°C | 23.9°C | 14 mm | 61% | 3.6 m/s | 6.7 |
| 2011 | 38.0°C | 31.9°C | 25.8°C | 40.3°C | 23.9°C | 20 mm | 62% | 3.6 m/s | 7 |
| 2010 | 34.9°C | 29.9°C | 24.8°C | 38.4°C | 21.4°C | 6 mm | 71% | 2.9 m/s | 6.8 |
| 2009 | 37.8°C | 31.7°C | 25.5°C | 40.4°C | 23.7°C | 29 mm | 60% | 3.7 m/s | 6.8 |
| 2008 ❄️ | 33.3°C | 29.0°C | 24.8°C | 37.6°C | 22.8°C | 154 mm | 77% | 3.1 m/s | 5.7 |
| 2007 | 33.3°C | 29.1°C | 24.9°C | 36.3°C | 23.3°C | 97 mm | 76% | 2.7 m/s | 6 |
| 2006 | 35.4°C | 30.6°C | 25.7°C | 38.6°C | 24.1°C | 9 mm | 67% | 3.3 m/s | 6.5 |
| 2005 | 35.4°C | 30.3°C | 25.3°C | 41.2°C | 23.1°C | 7 mm | 69% | 3.1 m/s | 6.8 |
| 2004 | 36.4°C | 30.8°C | 25.2°C | 39.0°C | 21.4°C | 52 mm | 65% | 3.2 m/s | 6.6 |
| 2003 | 35.4°C | 30.2°C | 25.1°C | 40.4°C | 24.2°C | 69 mm | 68% | 3.2 m/s | 6.5 |
| 2002 | 35.8°C | 30.6°C | 25.4°C | 39.9°C | 23.7°C | 19 mm | 66% | 3.4 m/s | 6.6 |
| 2001 | 36.1°C | 30.8°C | 25.6°C | 39.6°C | 24.3°C | 81 mm | 66% | 3.9 m/s | 6.4 |
| 2000 | 35.2°C | 30.1°C | 24.9°C | 39.4°C | 23.2°C | 47 mm | 65% | 3.1 m/s | 6.4 |
| 1999 | 35.8°C | 30.3°C | 24.8°C | 39.6°C | 22.8°C | 70 mm | 66% | 3.2 m/s | 6.6 |
| 1998 | 36.7°C | 31.4°C | 26.1°C | 40.9°C | 24.5°C | 44 mm | 64% | 3.2 m/s | 6.4 |
| 1997 | 37.0°C | 31.2°C | 25.4°C | 40.1°C | 23.8°C | 16 mm | 62% | 3.8 m/s | 6.8 |
| 1996 | 34.0°C | 29.4°C | 24.9°C | 39.8°C | 22.7°C | 137 mm | 71% | 3.7 m/s | 5.9 |
| 1995 | 33.7°C | 29.4°C | 25.1°C | 37.6°C | 22.7°C | 169 mm | 73% | 2.5 m/s | 5.8 |
| 1994 | 35.0°C | 29.9°C | 24.7°C | 38.5°C | 22.5°C | 46 mm | 67% | 3.2 m/s | 6.1 |
| 1993 | 35.7°C | 30.2°C | 24.7°C | 37.6°C | 23.2°C | 3 mm | 66% | 3.9 m/s | 6.8 |
| 1992 | 35.2°C | 29.8°C | 24.3°C | 38.5°C | 21.3°C | 65 mm | 67% | 3 m/s | 6.4 |
| 1991 | 36.4°C | 30.5°C | 24.6°C | 39.0°C | 22.7°C | 26 mm | 65% | 3.4 m/s | 6.5 |
| 1990 | 35.7°C | 30.3°C | 24.9°C | 38.4°C | 23.5°C | 57 mm | 65% | 3.7 m/s | 6.3 |
| 1989 | 35.6°C | 30.2°C | 24.8°C | 39.7°C | 23.1°C | 67 mm | 66% | 3.5 m/s | 6.4 |
| 1988 | 34.3°C | 29.5°C | 24.7°C | 39.8°C | 23.4°C | 114 mm | 72% | 2.9 m/s | 5.8 |
| 1987 | 34.9°C | 29.8°C | 24.7°C | 37.7°C | 23.6°C | 51 mm | 70% | 3.7 m/s | 6.6 |
| 1986 | 35.5°C | 30.0°C | 24.6°C | 40.4°C | 22.9°C | 27 mm | 65% | 3.4 m/s | 6.5 |
| 1985 | 36.2°C | 30.4°C | 24.5°C | 38.1°C | 23.3°C | 49 mm | 65% | 3.6 m/s | 6.8 |
| 1984 | 35.8°C | 30.2°C | 24.6°C | 38.1°C | 22.6°C | 21 mm | 63% | 3.6 m/s | 6.2 |
| 1983 | 34.2°C | 29.4°C | 24.5°C | 38.5°C | 22.8°C | 87 mm | 71% | 3 m/s | — |
| 1982 | 35.7°C | 30.2°C | 24.8°C | 39.1°C | 23.0°C | 18 mm | 64% | 3.7 m/s | — |
| 1981 🌧️ | 34.2°C | 29.5°C | 24.8°C | 37.8°C | 23.5°C | 170 mm | 71% | 3.1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 35.8°C with lows near 25.2°C (mean 30.5°C), based on 45 years of NASA POWER data.
August averages 52 mm of rainfall in Mcallen, about average for rainfall. The wettest on record was 170 mm in 1981.
The hottest August reached 42.6°C in 2023. The coldest dipped to 21.3°C in 1992.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.1°C. Daytime highs moved from 35.2°C to 36.4°C and overnight lows from 24.6°C to 25.7°C over the same span.
August is one of the warmer months of the year in Mcallen and about average for rainfall, so plan for around 35.8°C daytime highs and 25.2°C at night.
Not quite — August is the 12th coolest month in Mcallen, averaging 30.5°C.
For August in Mcallen, pack light, breathable clothing and sun protection, with typical highs of 35.8°C and lows of 25.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 67% — moderately humid.
Average wind speed in August is 3.3 m/s. The windiest August on record averaged 3.9 m/s (1993).
The wettest August on record was 1981 with 170 mm. On average, August sees 52 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Mcallen behaves each August, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for August specifically, along with year-by-year records and how the month has changed over the decades.
