May is one of the warmer months of the year in Harlingen, with average highs near 32.6°C and lows around 23.2°C (mean 27.9°C). It is a relatively wet time of year, averaging 70 mm of rainfall and 72% relative humidity across the period.
May is one of the warmer months of the year in Harlingen. Across 45 years of records, the warmest May in Harlingen was 2024 — when the month averaged 31.3°C — while the coldest was 1992 at 25.2°C. Typical May days reach 32.6°C with nights near 23.2°C. The long-term trend is warming, about 0.3°C per decade.
May is a relatively wet time of year in Harlingen, averaging 70 mm of rainfall. The wettest May on record was 1992 with 186 mm, while the driest was 1998 at 0 mm.
Relative humidity in Harlingen during May averages 72%. The most humid May was 1997 at 81%, and the least humid was 2017 at 67%.
May receives about 5.9 kWh/m²/day of solar energy in Harlingen. The sunniest May was 2018 at 6.8 kWh/m²/day, and the cloudiest were 1992 and 2015 at 5.2.
Average wind speed in Harlingen during May is 3.9 m/s. The windiest May was 1996 at 4.9 m/s, while the calmest was 2023 at 2.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 27.3°C | 27.8°C | 28.1°C | 27.9°C | 28.8°C | +1.5°C |
| Avg High | 32.1°C | 32.6°C | 32.9°C | 32.5°C | 33.3°C | +1.2°C |
| Avg Low | 22.5°C | 22.9°C | 23.3°C | 23.3°C | 24.3°C | +1.8°C |
| Avg Rain | 83 mm | 74 mm | 41 mm | 65 mm | 100 mm | +17 mm |
May temperatures in Harlingen have risen by about 1.9°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 13°C (2013) to a record high of 42.7°C (2024).
Rainfall in May is a relatively wet time of year, averaging 70 mm, with a wettest year of 186 mm.
A good time to visit Harlingen
May is a good time to visit Harlingen, with days averaging 32.6°C and nights around 23.2°C (mean 27.9°C, warmer than Harlingen's yearly average) and moderate rainfall. March and November are marginally more temperate, but May still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 34.0°C | 29.2°C | 24.5°C | 37.0°C | 18.3°C | 72 mm | 74% | 3.9 m/s | 5.9 |
| 2024 🔥 | 36.3°C | 31.3°C | 26.2°C | 42.7°C | 23.2°C | 19 mm | 73% | 3.9 m/s | 5.4 |
| 2023 | 31.7°C | 27.5°C | 23.3°C | 34.4°C | 19.3°C | 102 mm | 77% | 2.7 m/s | 5.6 |
| 2022 | 33.5°C | 28.9°C | 24.4°C | 36.3°C | 22.8°C | 93 mm | 74% | 4.4 m/s | 6.6 |
| 2021 | 31.6°C | 27.5°C | 23.5°C | 36.7°C | 19.9°C | 181 mm | 78% | 3.9 m/s | 5.5 |
| 2020 | 32.6°C | 28.4°C | 24.2°C | 36.0°C | 19.3°C | 130 mm | 74% | 3.9 m/s | 6 |
| 2019 | 33.6°C | 29.1°C | 24.6°C | 36.5°C | 20.8°C | 45 mm | 75% | 4.3 m/s | 5.5 |
| 2018 | 33.7°C | 28.7°C | 23.7°C | 36.8°C | 19.2°C | 30 mm | 68% | 3.8 m/s | 6.8 |
| 2017 | 33.3°C | 28.4°C | 23.5°C | 36.7°C | 17.7°C | 55 mm | 67% | 4.1 m/s | 5.9 |
| 2016 | 32.3°C | 28.0°C | 23.7°C | 35.2°C | 17.6°C | 120 mm | 73% | 3.6 m/s | 5.5 |
| 2015 | 30.7°C | 27.4°C | 24.0°C | 32.9°C | 16.8°C | 179 mm | 80% | 4.2 m/s | 5.2 |
| 2014 | 30.7°C | 25.9°C | 21.2°C | 35.6°C | 14.2°C | 73 mm | 69% | 4.2 m/s | 6.2 |
| 2013 | 31.4°C | 26.7°C | 22.1°C | 35.6°C | 13.0°C | 38 mm | 71% | 4.3 m/s | 5.8 |
| 2012 | 33.0°C | 28.2°C | 23.4°C | 35.8°C | 19.2°C | 47 mm | 70% | 3.8 m/s | 6.5 |
| 2011 | 33.4°C | 28.4°C | 23.4°C | 37.5°C | 16.5°C | 5 mm | 68% | 4.8 m/s | 6 |
| 2010 | 33.1°C | 28.1°C | 23.1°C | 36.2°C | 16.9°C | 60 mm | 71% | 4.1 m/s | 6.3 |
| 2009 | 32.9°C | 28.1°C | 23.2°C | 36.4°C | 17.9°C | 66 mm | 70% | 4 m/s | 6.3 |
| 2008 | 33.8°C | 28.7°C | 23.6°C | 39.3°C | 18.0°C | 20 mm | 71% | 4.2 m/s | 6.1 |
| 2007 | 31.7°C | 27.3°C | 22.9°C | 34.4°C | 19.7°C | 64 mm | 72% | 3.6 m/s | 5.7 |
| 2006 | 33.1°C | 28.4°C | 23.6°C | 36.8°C | 18.4°C | 59 mm | 68% | 4.1 m/s | 6.3 |
| 2005 | 32.6°C | 27.6°C | 22.7°C | 38.7°C | 17.4°C | 31 mm | 69% | 3.7 m/s | 5.9 |
| 2004 | 31.0°C | 26.7°C | 22.3°C | 37.4°C | 14.0°C | 56 mm | 74% | 4.4 m/s | 6.1 |
| 2003 | 34.9°C | 29.6°C | 24.3°C | 38.7°C | 22.3°C | 12 mm | 70% | 4.2 m/s | 5.9 |
| 2002 | 33.2°C | 28.3°C | 23.4°C | 37.3°C | 18.0°C | 38 mm | 68% | 4.6 m/s | 6.4 |
| 2001 | 32.8°C | 27.9°C | 22.9°C | 36.1°C | 20.0°C | 12 mm | 70% | 4 m/s | 6.4 |
| 2000 | 33.4°C | 28.8°C | 24.2°C | 36.6°C | 22.4°C | 51 mm | 73% | 4.5 m/s | 6.2 |
| 1999 | 34.2°C | 28.9°C | 23.7°C | 41.7°C | 20.7°C | 41 mm | 70% | 4.1 m/s | 6 |
| 1998 | 35.9°C | 29.4°C | 22.8°C | 39.1°C | 18.6°C | 0 mm | 68% | 4.1 m/s | 6.3 |
| 1997 | 29.9°C | 25.6°C | 21.4°C | 34.9°C | 16.9°C | 96 mm | 81% | 2.9 m/s | 5.8 |
| 1996 | 33.2°C | 28.5°C | 23.7°C | 37.6°C | 17.6°C | 16 mm | 71% | 4.9 m/s | 6.4 |
| 1995 | 34.1°C | 29.1°C | 24.1°C | 39.5°C | 20.1°C | 74 mm | 70% | 4.3 m/s | 5.7 |
| 1994 | 33.2°C | 28.2°C | 23.2°C | 37.5°C | 19.9°C | 32 mm | 71% | 3.5 m/s | 6 |
| 1993 | 30.9°C | 26.1°C | 21.3°C | 33.9°C | 16.9°C | 155 mm | 75% | 3.4 m/s | 5.7 |
| 1992 ❄️ 🌧️ | 29.2°C | 25.2°C | 21.3°C | 34.0°C | 15.3°C | 186 mm | 79% | 3.2 m/s | 5.2 |
| 1991 | 32.8°C | 28.3°C | 23.8°C | 36.3°C | 20.6°C | 85 mm | 75% | 3.6 m/s | 5.8 |
| 1990 | 32.9°C | 28.2°C | 23.4°C | 37.9°C | 15.5°C | 58 mm | 74% | 4.2 m/s | 5.6 |
| 1989 | 33.7°C | 28.6°C | 23.5°C | 38.3°C | 18.7°C | 12 mm | 72% | 4.5 m/s | 6.6 |
| 1988 | 32.2°C | 27.0°C | 21.9°C | 36.0°C | 18.8°C | 16 mm | 67% | 3.6 m/s | 5.8 |
| 1987 | 32.2°C | 27.3°C | 22.4°C | 36.7°C | 18.2°C | 83 mm | 75% | 3.5 m/s | 5.5 |
| 1986 | 32.1°C | 27.4°C | 22.7°C | 34.9°C | 18.8°C | 100 mm | 72% | 3.5 m/s | 5.4 |
| 1985 | 32.3°C | 27.4°C | 22.5°C | 36.5°C | 18.3°C | 89 mm | 72% | 3.2 m/s | 6.1 |
| 1984 | 32.0°C | 27.0°C | 22.0°C | 41.0°C | 16.7°C | 88 mm | 71% | 3.8 m/s | 5.5 |
| 1983 | 32.3°C | 27.3°C | 22.3°C | 37.3°C | 17.1°C | 52 mm | 72% | 4.2 m/s | — |
| 1982 | 30.0°C | 26.2°C | 22.3°C | 33.8°C | 17.1°C | 168 mm | 80% | 3.8 m/s | — |
| 1981 | 31.8°C | 27.1°C | 22.5°C | 36.7°C | 18.4°C | 138 mm | 74% | 3.5 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 32.6°C with lows near 23.2°C (mean 27.9°C), based on 45 years of NASA POWER data.
May averages 70 mm of rainfall in Harlingen, a relatively wet time of year. The wettest on record was 186 mm in 1992.
The hottest May reached 42.7°C in 2024. The coldest dipped to 13°C in 2013.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.9°C. Daytime highs moved from 31.7°C to 33.4°C and overnight lows from 22.3°C to 24.4°C over the same span.
May is one of the warmer months of the year in Harlingen and a relatively wet time of year, so plan for around 32.6°C daytime highs and 23.2°C at night.
Not quite — May is the 8th coolest month in Harlingen, averaging 27.9°C.
For May in Harlingen, pack light, breathable clothing and sun protection, with typical highs of 32.6°C and lows of 23.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 72% — moderately humid.
Average wind speed in May is 3.9 m/s. The windiest May on record averaged 4.9 m/s (1996).
The wettest May on record was 1992 with 186 mm. On average, May sees 70 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 Harlingen behaves each May, 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 May specifically, along with year-by-year records and how the month has changed over the decades.
