April is close to Harlingen's year-round average, with average highs near 30.5°C and lows around 19.9°C (mean 25.2°C). It is one of the drier months, averaging 41 mm of rainfall and 71% relative humidity across the period.
April is close to Harlingen's year-round average. Across 45 years of records, the warmest April in Harlingen was 2020 — when the month averaged 27.5°C — while the coldest was 1997 at 22.2°C. Typical April days reach 30.5°C with nights near 19.9°C. The long-term trend is warming, about 0.3°C per decade.
April is one of the drier months in Harlingen, averaging 41 mm of rainfall. The wettest April on record was 1997 with 142 mm, while the driest was 1983 at 0 mm.
Relative humidity in Harlingen during April averages 71%. The most humid April was 2015 at 82%, and the least humid was 2005 at 63%.
April receives about 5.4 kWh/m²/day of solar energy in Harlingen. The sunniest April was 2012 at 6.2 kWh/m²/day, and the cloudiest were 1997 and 2015 at 4.4.
Average wind speed in Harlingen during April is 4.1 m/s. The windiest April was 2011 at 5.3 m/s, while the calmest were 1988 and 1992 at 3.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 24.8°C | 24.7°C | 25.5°C | 25.4°C | 26.1°C | +1.3°C |
| Avg High | 30.5°C | 30.0°C | 30.6°C | 30.6°C | 31.1°C | +0.6°C |
| Avg Low | 19.1°C | 19.4°C | 20.4°C | 20.2°C | 21.0°C | +1.9°C |
| Avg Rain | 34 mm | 57 mm | 34 mm | 39 mm | 39 mm | +5 mm |
April temperatures in Harlingen have risen by about 0.7°C between 1981–1985 and 2021–2025.
April has ranged from a record low of 8.7°C (1996) to a record high of 41.1°C (1984).
Rainfall in April is one of the drier months, averaging 41 mm, with a wettest year of 142 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0.4°C per decade, narrowing the gap between day and night.
A good time to visit Harlingen
April is a good time to visit Harlingen, with days averaging 30.5°C and nights around 19.9°C (mean 25.2°C, close to Harlingen's yearly average) and moderate rainfall. March and November are marginally more temperate, but April still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 30.7°C | 25.9°C | 21.0°C | 33.7°C | 11.2°C | 16 mm | 71% | 4.6 m/s | 5.9 |
| 2024 | 31.5°C | 26.4°C | 21.3°C | 36.9°C | 13.4°C | 13 mm | 71% | 4.3 m/s | 5.1 |
| 2023 | 29.7°C | 24.7°C | 19.7°C | 36.8°C | 12.9°C | 102 mm | 77% | 3.6 m/s | 4.7 |
| 2022 | 31.6°C | 26.6°C | 21.6°C | 40.2°C | 15.5°C | 56 mm | 72% | 4.3 m/s | 5.5 |
| 2021 | 30.6°C | 25.4°C | 20.2°C | 36.2°C | 14.6°C | 34 mm | 72% | 4 m/s | 4.8 |
| 2020 🔥 | 32.8°C | 27.5°C | 22.3°C | 38.9°C | 17.5°C | 13 mm | 70% | 3.8 m/s | 4.8 |
| 2019 | 30.5°C | 24.8°C | 19.0°C | 35.7°C | 9.8°C | 14 mm | 69% | 4.1 m/s | 5.7 |
| 2018 | 29.6°C | 24.5°C | 19.4°C | 33.8°C | 11.7°C | 47 mm | 69% | 4.3 m/s | 5.3 |
| 2017 | 31.7°C | 26.5°C | 21.4°C | 38.6°C | 16.7°C | 22 mm | 66% | 4.1 m/s | 5.8 |
| 2016 | 31.1°C | 26.0°C | 20.8°C | 35.6°C | 12.2°C | 42 mm | 72% | 3.5 m/s | 5.3 |
| 2015 | 29.3°C | 25.3°C | 21.2°C | 35.5°C | 14.8°C | 98 mm | 82% | 3.4 m/s | 4.4 |
| 2014 | 30.6°C | 24.9°C | 19.3°C | 40.2°C | 11.6°C | 2 mm | 70% | 4.3 m/s | 5.2 |
| 2013 | 29.8°C | 24.2°C | 18.5°C | 39.3°C | 13.4°C | 48 mm | 70% | 4.3 m/s | 5 |
| 2012 | 31.6°C | 26.5°C | 21.3°C | 36.0°C | 15.6°C | 25 mm | 69% | 4.2 m/s | 6.2 |
| 2011 | 32.8°C | 27.1°C | 21.5°C | 39.4°C | 17.3°C | 1 mm | 68% | 5.3 m/s | 6.1 |
| 2010 | 29.0°C | 24.3°C | 19.5°C | 37.7°C | 15.2°C | 86 mm | 75% | 3.9 m/s | 5.1 |
| 2009 | 31.3°C | 25.8°C | 20.2°C | 36.2°C | 12.5°C | 2 mm | 65% | 4.6 m/s | 5.7 |
| 2008 | 30.5°C | 25.3°C | 20.0°C | 38.7°C | 13.7°C | 62 mm | 67% | 4.4 m/s | 5.8 |
| 2007 | 29.2°C | 24.0°C | 18.8°C | 35.1°C | 9.6°C | 19 mm | 73% | 4 m/s | 5 |
| 2006 | 32.1°C | 26.9°C | 21.6°C | 36.5°C | 16.9°C | 7 mm | 71% | 4.5 m/s | 6 |
| 2005 | 31.0°C | 25.4°C | 19.8°C | 40.5°C | 12.6°C | 1 mm | 63% | 4.1 m/s | 5.5 |
| 2004 | 27.9°C | 23.7°C | 19.6°C | 31.4°C | 10.2°C | 131 mm | 78% | 4.2 m/s | 5.2 |
| 2003 | 30.1°C | 25.1°C | 20.1°C | 37.4°C | 10.8°C | 24 mm | 73% | 4.1 m/s | 4.7 |
| 2002 | 31.7°C | 26.8°C | 21.9°C | 36.2°C | 16.5°C | 23 mm | 74% | 4.7 m/s | 5.6 |
| 2001 | 30.9°C | 26.2°C | 21.4°C | 37.6°C | 16.7°C | 40 mm | 73% | 4.7 m/s | 5.5 |
| 2000 | 30.8°C | 25.6°C | 20.4°C | 38.1°C | 13.7°C | 26 mm | 70% | 4.2 m/s | 5.7 |
| 1999 | 32.0°C | 26.7°C | 21.3°C | 36.3°C | 13.9°C | 4 mm | 71% | 4.8 m/s | 5.8 |
| 1998 | 30.7°C | 24.6°C | 18.5°C | 39.5°C | 14.9°C | 2 mm | 66% | 4 m/s | 5.8 |
| 1997 ❄️ 🌧️ | 26.7°C | 22.2°C | 17.8°C | 35.7°C | 11.4°C | 142 mm | 81% | 3.5 m/s | 4.4 |
| 1996 | 30.0°C | 23.7°C | 17.3°C | 36.9°C | 8.7°C | 23 mm | 68% | 4.3 m/s | 5.9 |
| 1995 | 30.7°C | 25.1°C | 19.6°C | 36.9°C | 15.4°C | 29 mm | 69% | 4.2 m/s | 5.5 |
| 1994 | 30.1°C | 24.8°C | 19.6°C | 35.2°C | 12.4°C | 39 mm | 75% | 3.9 m/s | 5 |
| 1993 | 29.5°C | 24.1°C | 18.8°C | 35.8°C | 13.2°C | 18 mm | 69% | 4.3 m/s | 5.6 |
| 1992 | 28.5°C | 23.7°C | 18.8°C | 34.5°C | 13.8°C | 118 mm | 77% | 3.2 m/s | 5.1 |
| 1991 | 31.9°C | 26.8°C | 21.6°C | 40.2°C | 14.0°C | 140 mm | 76% | 3.6 m/s | 4.9 |
| 1990 | 29.7°C | 25.0°C | 20.3°C | 35.7°C | 15.7°C | 52 mm | 76% | 4.3 m/s | 5 |
| 1989 | 30.4°C | 24.8°C | 19.2°C | 37.2°C | 13.4°C | 70 mm | 73% | 3.8 m/s | 5.2 |
| 1988 | 30.7°C | 24.6°C | 18.5°C | 37.8°C | 9.7°C | 11 mm | 69% | 3.2 m/s | 4.9 |
| 1987 | 28.7°C | 22.5°C | 16.3°C | 35.9°C | 9.3°C | 24 mm | 66% | 3.3 m/s | 5.6 |
| 1986 | 31.0°C | 25.9°C | 20.9°C | 35.5°C | 17.5°C | 31 mm | 71% | 3.9 m/s | 5.2 |
| 1985 | 29.8°C | 24.8°C | 19.8°C | 37.1°C | 13.3°C | 48 mm | 73% | 3.7 m/s | 5.2 |
| 1984 | 32.8°C | 26.0°C | 19.2°C | 41.1°C | 14.3°C | 1 mm | 63% | 3.9 m/s | 6 |
| 1983 | 30.1°C | 23.8°C | 17.4°C | 38.7°C | 10.8°C | 0 mm | 63% | 4.3 m/s | — |
| 1982 | 30.9°C | 25.5°C | 20.1°C | 38.6°C | 15.3°C | 69 mm | 74% | 4 m/s | — |
| 1981 | 30.1°C | 25.5°C | 20.9°C | 34.1°C | 15.9°C | 53 mm | 76% | 3.9 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 30.5°C with lows near 19.9°C (mean 25.2°C), based on 45 years of NASA POWER data.
April averages 41 mm of rainfall in Harlingen, one of the drier months. The wettest on record was 142 mm in 1997.
The hottest April reached 41.1°C in 1984. The coldest dipped to 8.7°C in 1996.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average April temperatures have risen by about 0.7°C. Daytime highs moved from 30.7°C to 30.8°C and overnight lows from 19.5°C to 20.8°C over the same span.
April is close to Harlingen's year-round average and one of the drier months, so plan for around 30.5°C daytime highs and 19.9°C at night.
Not quite — April is the 6th coolest month in Harlingen, averaging 25.2°C.
For April in Harlingen, pack light, breathable clothing and sun protection, with typical highs of 30.5°C and lows of 19.9°C.
Relative humidity in April averages 71% — moderately humid.
Average wind speed in April is 4.1 m/s. The windiest April on record averaged 5.3 m/s (2011).
The wettest April on record was 1997 with 142 mm. On average, April sees 41 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 April, 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 April specifically, along with year-by-year records and how the month has changed over the decades.
