Harlingen has a warm subtropical climate with warm summers and mild winters.
Temperatures peak in August and drop to their lowest in January, while rainfall is highest during autumn months.
Humidity remains moderate throughout the year, especially during winter months, creating warm and humid conditions.
| Month | 🌤️ | Avg High | Avg Temp | Avg Low | Record High | Record Low | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|---|---|
| January | ☀️ | 72.2°F | 63.4°F | 54.6°F | 91.8°F | 26.8°F | 75% | 29 | 3.7 | 3.01 |
| February | ☀️ | 75.8°F | 66.5°F | 57.3°F | 96.4°F | 25.5°F | 74% | 27 | 3.9 | 3.72 |
| March | 🌞 | 81.4°F | 71.8°F | 62.2°F | 101.5°F | 38.3°F | 71% | 33 | 4.1 | 4.62 |
| April | 🌞 | 86.9°F | 77.4°F | 67.9°F | 106.0°F | 47.7°F | 71% | 41 | 4.1 | 5.34 |
| May | 🌞 | 90.8°F | 82.2°F | 73.7°F | 108.9°F | 55.4°F | 72% | 70 | 3.9 | 5.93 |
| June | 🔥 | 93.7°F | 85.7°F | 77.8°F | 107.6°F | 64.9°F | 70% | 74 | 3.7 | 6.45 |
| July | 🔥 | 93.0°F | 85.7°F | 78.5°F | 103.6°F | 71.8°F | 71% | 63 | 3.6 | 6.51 |
| August | 🔥 | 93.8°F | 86.5°F | 79.2°F | 105.4°F | 72.9°F | 70% | 52 | 3.2 | 6.16 |
| September | ☔ | 90.7°F | 83.7°F | 76.7°F | 104.5°F | 59.7°F | 73% | 125 | 2.9 | 5.22 |
| October | 🌞 | 86.8°F | 78.8°F | 70.9°F | 100.6°F | 39.9°F | 72% | 70 | 3.2 | 4.52 |
| November | 🌞 | 80.0°F | 71.8°F | 63.5°F | 93.4°F | 37.9°F | 73% | 43 | 3.5 | 3.38 |
| December | ☀️ | 74.3°F | 65.6°F | 57.0°F | 90.9°F | 19.2°F | 75% | 30 | 3.5 | 2.74 |
Showing average climate conditions across 45 years (1981–2025)
🧥 Light layers are sufficient — this Mild Winter stays cool without prolonged hard freezes.
🌤️ Limit midday outdoor exposure and stay hydrated — this is an intense Hot Summer.
☔ Moderate Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025 climate normals · °F
Temperatures rise steadily from spring, peak in August, and gradually decline through autumn into winter.
These seasonal patterns offer comfortable conditions year-round, with warm summers and mild winters.
Monthly rainfall · 1981–2025 seasonal trends · mm/month
Rainfall is concentrated in the autumn months. Humidity stays moderate (around 72%), peaking during winter months, which creates warm and humid conditions.
☔ Moderate Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025
Across 45 years of records, Harlingen's temperature shows a slight warming trend over the past decade. Its hottest day reached 108.8°F in May 2024, and its coldest dropped to 19.3°F in December 1989. 2024 was the warmest year overall and 2010 the coolest.
The warmest year in Harlingen's recorded history was 2024 (avg: 79.2°F), while the coldest was 2010 (avg: 74.8°F).
Average annual high/low · Last 30 years · °F
Total annual precipitation · Last 30 years · mm/year
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|---|---|
2025 | 86.9°F | 78.4°F | 69.8°F | 100.9°F | 26.8°F | 660 | 72% | 3.5 m/s |
2024 🔥 | 87.6°F | 79.2°F | 70.7°F | 108.9°F | 30.2°F | 719 | 74% | 3.3 m/s |
2023 | 87.3°F | 78.6°F | 69.8°F | 105.4°F | 40.1°F | 551 | 73% | 3.5 m/s |
2022 | 84.9°F | 76.3°F | 67.6°F | 104.4°F | 30.2°F | 551 | 72% | 3.6 m/s |
2021 | 84.7°F | 76.6°F | 68.5°F | 98.4°F | 25.5°F | 921 | 75% | 3.4 m/s |
2020 | 86.5°F | 78.1°F | 69.6°F | 102.0°F | 37.6°F | 613 | 72% | 3.6 m/s |
2019 | 85.6°F | 77.2°F | 68.7°F | 107.6°F | 39.0°F | 541 | 73% | 3.7 m/s |
2018 | 84.6°F | 76.5°F | 68.2°F | 100.9°F | 33.3°F | 596 | 73% | 3.7 m/s |
2017 | 87.1°F | 78.6°F | 70.0°F | 102.9°F | 32.2°F | 512 | 70% | 3.7 m/s |
2016 | 86.4°F | 78.1°F | 69.8°F | 100.4°F | 37.8°F | 543 | 71% | 3.5 m/s |
Showing 1 to 10 of 45 years
Based on 45 years of data (1981–2025), August is typically the hottest month in Harlingen, Texas, with average high temperatures around 93.8°F.
January is the coldest month in Harlingen, with average low temperatures around 54.6°F.
September receives the most rainfall with approximately 125 mm, while February is the driest with 27 mm.
The highest recorded temperature was 108.8°F in May 2024. This is part of the historical record spanning 1981–2025.
The lowest recorded temperature was 19.3°F in December 1989.
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
Harlingen receives the most sunlight in July with an average solar radiation of 6.51 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning and agriculture in Texas.
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.
