Harlingen, Texas climate: Normal weather by month, frost dates and records
Harlingen's normal year runs from 50°F January nights to 97°F August afternoons, with 24.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 23.8°C, January lows of 10°C, August highs of 36°C, 611 mm of precipitation a year.
- NOAA stationHarlingen Rio Grande Airport
- Station IDUSW00012904
- Location26.23°N 97.65°W
- Elevation34 ft (10 m)
- Population72,234
On October 23, the normal high in Harlingen is 86°F and the normal low 64°F, and the chance of measurable rain or snow is 28%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Harlingen.
- Jan 72° 50°
- Feb 76° 54°
- Mar 81° 59°
- Apr 87° 65°
- May 91° 71°
- Jun 95° 75°
- Jul 96° 75°
- Aug 97° 75°
- Sep 92° 73°
- Oct 88° 66°
- Nov 79° 57°
- Dec 73° 52°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Harlingen each month?
August is the warmest month, with normal highs of 97°F; January the coldest, with normal lows of 50°F. The most precipitation falls in September (5.31 in), the least in February (0.73 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 72°F | 50°F | 60.8°F | 1.05 | 8 | <1 | 1 | 10 h 40 min |
| February | 76°F | 54°F | 64.9°F | 0.73 | 6 | 1 | <1 | 11 h 20 min |
| March | 81°F | 59°F | 70.2°F | 1.31 | 6 | 3 | <1 | 12 h |
| April | 87°F | 65°F | 75.8°F | 1.46 | 5 | 11 | <1 | 12 h 50 min |
| May | 91°F | 71°F | 81.2°F | 2.50 | 6 | 22 | <1 | 13 h 20 min |
| June | 95°F | 75°F | 84.8°F | 2.26 | 6 | 28 | <1 | 13 h 50 min |
| July | 96°F | 75°F | 85.8°F | 1.76 | 6 | 30 | <1 | 13 h 40 min |
| August | 97°F | 75°F | 86.2°F | 1.92 | 5 | 30 | <1 | 13 h 10 min |
| September | 92°F | 73°F | 82.3°F | 5.31 | 11 | 22 | <1 | 12 h 20 min |
| October | 88°F | 66°F | 76.6°F | 2.71 | 9 | 14 | <1 | 11 h 30 min |
| November | 79°F | 57°F | 68.4°F | 1.81 | 8 | 2 | <1 | 10 h 50 min |
| December | 73°F | 52°F | 62.4°F | 1.22 | 8 | <1 | 1 | 10 h 30 min |
| Year (annual) | 86°F | 64°F | 74.9°F | 24.04 | 84 | 163 | 2 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 22°C | 10°C | 16.0°C | 27 mm |
| February | 24°C | 12°C | 18.3°C | 19 mm |
| March | 27°C | 15°C | 21.2°C | 33 mm |
| April | 30°C | 18°C | 24.3°C | 37 mm |
| May | 33°C | 22°C | 27.3°C | 64 mm |
| June | 35°C | 24°C | 29.3°C | 57 mm |
| July | 36°C | 24°C | 29.9°C | 45 mm |
| August | 36°C | 24°C | 30.1°C | 49 mm |
| September | 33°C | 23°C | 27.9°C | 135 mm |
| October | 31°C | 19°C | 24.8°C | 69 mm |
| November | 26°C | 14°C | 20.2°C | 46 mm |
| December | 23°C | 11°C | 16.9°C | 31 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00012904; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Harlingen?
Normal highs sit between 65°F and 85°F in January, February, March, November and December. Of those, February has the fewest days with rain (6).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00012904.
When is the last frost in Harlingen?
In Harlingen, the last spring frost (32°F) comes after January 8 in half of years and after February 17 in one year in ten; the first autumn frost comes before December 29 in half of years and before December 2 in one year in ten. A night at 32°F or colder comes at all in 61% of years here (NOAA).
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- January 81 year in 10 after February 17; 9 in 10 after December 12
- First autumn frost, half of years before
- December 291 year in 10 before December 2; 9 in 10 before February 1
NOAA puts the median frost-free season at 357 days, and the season without a hard freeze (28°F) at 365 days.
A hard freeze (28°F) comes after January 2 in half of springs and before January 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Harlingen in zone 10a across its 2 ZIP code areas (10a in 78550, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Harlingen's NOAA station is in zone 10a: the coldest night of a typical year reaches 32°F (24 complete years).
Frost dates for every NOAA station in Texas · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00012904; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Harlingen ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Harlingen's 2 ZIP code areas are all in zone 10a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Harlingen?
In a normal year in Harlingen, 163 days a year reach 90°F (17 of them 100°F or more), 2 nights fall to 32°F or colder and 84 days bring measurable precipitation.
- Days at 90°F or more
- 163a normal year
- Days at 100°F or more
- 17a normal year
- Nights at 32°F or colder
- 2a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 84a normal year
The highest temperature in this station's record (since 1952) is 107°F, on May 9, 2024; the lowest is 17°F, on January 12, 1962.
The wettest calendar year on that record is 2021, with 39.03 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00012904; records: ACIS (NOAA Regional Climate Centers), station USW00012904. Records use complete months only; a month missing more than three days is left out.
How sunny is Harlingen?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Harlingen, 4.8 kWh per square metre a day. August is the sunniest month (87%) and December the cloudiest (68%). Among the 459 U.S. places of 50,000 or more, that ranks tied 176th (with 33 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 69% | 3.1 |
| February | 70% | 3.7 |
| March | 73% | 4.6 |
| April | 77% | 5.4 |
| May | 82% | 6.0 |
| June | 86% | 6.5 |
| July | 86% | 6.5 |
| August | 87% | 6.2 |
| September | 80% | 5.2 |
| October | 83% | 4.6 |
| November | 76% | 3.5 |
| December | 68% | 2.8 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Harlingen need?
A normal year in Harlingen brings 569 heating degree days, 89% fewer than the median U.S. place (5,373), and 4,220 cooling degree days, 4.6 times the median (908). No month reaches 300 heating degree days. For gardens and crops, NOAA counts 9,166 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 190 | 59 |
| February | 105 | 102 |
| March | 40 | 201 |
| April | 7 | 332 |
| May | 0 | 502 |
| June | 0 | 594 |
| July | 0 | 643 |
| August | 0 | 659 |
| September | 0 | 521 |
| October | 5 | 364 |
| November | 62 | 162 |
| December | 162 | 82 |
| Year (annual) | 569 | 4,220 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00012904. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Harlingen been warmer than normal lately?
2025 averaged 75.9°F, 1.0°F above the 1991-2020 normal of 74.9°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 75.0°F | +0.1°F | 39.03 |
| 2022 | 74.3°F | −0.6°F | 24.16 |
| 2023 | 76.4°F | +1.5°F | 27.87 |
| 2024 | 76.3°F | +1.4°F | 36.01 |
| 2025 | 75.9°F | +1.0°F | 36.40 |
Source: observed years: ACIS, station USW00012904. A year counts only with all twelve months complete.
How does Harlingen's climate compare?
Harlingen is warmer than 316 of the other 320 places with their own NOAA record in Texas, and wetter than 100. Across the 7,247 U.S. stations with normals, its annual mean of 74.9°F is warmer than 99%.
In the Köppen classification computed from these normals, Harlingen is BSh: hot semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Harlingen share this climate record?
22 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- San Benito, TX24,712 people · 7 mi S
- Primera, TX5,449 people · 6 mi W
- Combes, TX3,259 people · 5 mi W
- La Paloma, TX2,836 people · 12 mi S
- Encantada-Ranchito-El Calaboz, TX2,328 people · 13 mi S
- Rio Hondo, TX2,311 people · 5 mi E
- Palmer, TX1,606 people · 11 mi S
- Palm Valley, TX1,353 people · 6 mi W
- Rice Tracts, TX1,117 people · 12 mi S
- Los Indios, TX1,042 people · 13 mi S
- Las Palmas II, TX770 people · 5 mi W
- Arroyo Colorado Estates, TX587 people · 4 mi SE
- Green Valley Farms, TX469 people · 9 mi SE
- Juarez, TX380 people · 5 mi W
- Arroyo Gardens, TX248 people · 10 mi E
- Lozano, TX153 people · 7 mi E
- Rangerville, TX111 people · 10 mi SW
- Lago, TX87 people · 10 mi S
- Lasana, TX62 people · 3 mi NW
- Villa del Sol, TX61 people · 5 mi SE
- Santa Monica, TX10 people · 11 mi NE
- El Camino Angosto, TX0 people · 8 mi S
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Harlingen's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Harlingen. This page uses Harlingen Rio Grande Airport; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Harlingen station USC00413943 | 2 mi SW | 38 ft | 75.6°F | 51°F | 97°F | 28.2 | 0 | January 9 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Harlingen's climate
What is the coldest month in Harlingen?
January, with a normal high of 72°F and a normal low of 50°F. The warmest is August (97°F by day, 75°F at night).
Does it snow in Harlingen?
Rarely. NOAA publishes no 1991-2020 snowfall normal for Harlingen's NOAA station; Harlingen's own co-op station Harlingen station records 0 inches of snow in a normal year.
What is the rainiest month in Harlingen?
September, with 5.31 in of precipitation in a normal year; the driest is February with 0.73 in.
What plant hardiness zone is Harlingen in?
The USDA's 2023 map puts Harlingen in zone 10a across its 2 ZIP code areas (10a in 78550, the largest). By the same method at Harlingen's NOAA station, the coldest night of a typical year reaches 32°F (24 years, 1991-2020): zone 10a.
How late can frost come in Harlingen?
In half of years the last 32°F night comes after January 8; in one year in ten it comes after February 17. Waiting until February 17 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Harlingen in OctoberThis month day by day, its records and recent years
- Texas climateThe statewide normals and every place in the state
- Santa Rosa, TX14 miles from this station, 74.7°F a year
- Raymondville, TX18 miles from this station, 74.4°F a year
- Port Isabel, TX20 miles from this station, 74.8°F a year
- Weslaco, TX20 miles from this station, 75.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made