Weslaco, Texas climate: Normal weather by month, frost dates and records
Weslaco's normal year runs from 50°F January nights to 97°F August afternoons, with 25.7 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 23.9°C, January lows of 10°C, August highs of 36°C, 654 mm of precipitation a year.
- NOAA stationWeslaco
- Station IDUSC00419588
- Location26.18°N 97.97°W
- Elevation75 ft (23 m)
- Population43,864
On October 23, the normal high in Weslaco is 86°F and the normal low 64°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Weslaco.
- Jan 71° 50°
- Feb 75° 54°
- Mar 81° 60°
- Apr 86° 65°
- May 90° 72°
- Jun 95° 76°
- Jul 96° 77°
- Aug 97° 76°
- Sep 92° 73°
- Oct 87° 66°
- Nov 80° 58°
- Dec 72° 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 Weslaco 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 (5.64 in), the least in February (0.95 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 71°F | 50°F | 60.7°F | 1.02 | – | <1 | <1 | 10 h 40 min |
| February | 75°F | 54°F | 64.4°F | 0.95 | – | 1 | 1 | 11 h 20 min |
| March | 81°F | 60°F | 70.4°F | 1.45 | – | 3 | <1 | 12 h |
| April | 86°F | 65°F | 75.7°F | 1.46 | – | 9 | <1 | 12 h 50 min |
| May | 90°F | 72°F | 80.9°F | 2.61 | – | 21 | <1 | 13 h 20 min |
| June | 95°F | 76°F | 85.1°F | 2.79 | – | 27 | <1 | 13 h 50 min |
| July | 96°F | 77°F | 86.1°F | 2.24 | – | 29 | <1 | 13 h 40 min |
| August | 97°F | 76°F | 86.9°F | 1.87 | – | 30 | <1 | 13 h 10 min |
| September | 92°F | 73°F | 82.4°F | 5.64 | – | 22 | <1 | 12 h 20 min |
| October | 87°F | 66°F | 76.6°F | 2.84 | – | 15 | <1 | 11 h 30 min |
| November | 80°F | 58°F | 69.2°F | 1.61 | – | 2 | <1 | 10 h 50 min |
| December | 72°F | 52°F | 61.8°F | 1.25 | – | <1 | <1 | 10 h 30 min |
| Year (annual) | 85°F | 65°F | 75.0°F | 25.73 | – | 160 | 1 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 22°C | 10°C | 15.9°C | 26 mm |
| February | 24°C | 12°C | 18.0°C | 24 mm |
| March | 27°C | 16°C | 21.3°C | 37 mm |
| April | 30°C | 18°C | 24.3°C | 37 mm |
| May | 32°C | 22°C | 27.2°C | 66 mm |
| June | 35°C | 24°C | 29.5°C | 71 mm |
| July | 35°C | 25°C | 30.1°C | 57 mm |
| August | 36°C | 25°C | 30.5°C | 47 mm |
| September | 33°C | 23°C | 28.0°C | 143 mm |
| October | 31°C | 19°C | 24.8°C | 72 mm |
| November | 27°C | 15°C | 20.7°C | 41 mm |
| December | 22°C | 11°C | 16.6°C | 32 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00419588; 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 Weslaco?
Normal highs sit between 65°F and 85°F in January, February, March, November and December.
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 USC00419588.
When is the last frost in Weslaco?
A night at 32°F or colder comes in only 44% of years in Weslaco (NOAA). NOAA's median date of the last spring frost is January 8 and of the first autumn frost December 31.
NOAA puts the median frost-free season at 365 days, and the season without a hard freeze (28°F) at 365 days.
The USDA's 2023 Plant Hardiness Zone Map puts Weslaco in zone 10a across its 2 ZIP code areas (10a in 78596, the largest).
Frost dates for every NOAA station in Texas · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00419588; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Weslaco ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Weslaco'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 Weslaco?
In a normal year in Weslaco, 160 days a year reach 90°F (17 of them 100°F or more) and 1 night falls to 32°F or colder.
- Days at 90°F or more
- 160a normal year
- Days at 100°F or more
- 17a normal year
- Nights at 32°F or colder
- 1a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
The highest temperature in this station's record (since 1914) is 110°F, on April 17, 1920; the lowest is 16°F, on January 12, 1962.
The wettest calendar year on that record is 1976, with 35.99 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00419588; records: ACIS (NOAA Regional Climate Centers), station USC00419588. Records use complete months only; a month missing more than three days is left out.
How sunny is Weslaco?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Weslaco, 4.8 kWh per square metre a day. August is the sunniest month (87%) and December the cloudiest (68%).
| 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 Weslaco need?
A normal year in Weslaco brings 580 heating degree days, 89% fewer than the median U.S. place (5,373), and 4,251 cooling degree days, 4.7 times the median (908). No month reaches 300 heating degree days. For gardens and crops, NOAA counts 9,194 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 187 | 53 |
| February | 107 | 91 |
| March | 39 | 206 |
| April | 7 | 328 |
| May | 0 | 493 |
| June | 0 | 601 |
| July | 0 | 654 |
| August | 0 | 677 |
| September | 0 | 522 |
| October | 7 | 366 |
| November | 61 | 185 |
| December | 173 | 74 |
| Year (annual) | 580 | 4,251 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00419588. 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 Weslaco been warmer than normal lately?
2024 averaged 77.0°F, 2.0°F above the 1991-2020 normal of 75.0°F.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2024 | 77.0°F | +2.0°F | 21.78 |
Over 48 complete years from 1924 to 2025, the station's annual mean temperature rose at a fitted 4.6°F per century (+0.26°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00419588; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Weslaco's climate compare?
Weslaco is warmer than 317 of the other 320 places with their own NOAA record in Texas, and wetter than 122. Across the 7,247 U.S. stations with normals, its annual mean of 75.0°F is warmer than 99%.
In the Köppen classification computed from these normals, Weslaco is Cfa: temperate, no dry season, hot summer. 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 Weslaco share this climate record?
19 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.
- Mercedes, TX17,535 people · 4 mi SE
- Donna, TX16,876 people · 4 mi W
- Mila Doce, TX8,298 people · 3 mi N
- Olivarez, TX6,566 people · 4 mi N
- Progreso, TX5,182 people · 6 mi S
- Midway North, TX3,514 people · 3 mi W
- Scissors, TX3,196 people · 6 mi SW
- South Alamo, TX3,114 people · 9 mi W
- Midway South, TX2,858 people · 3 mi SW
- Indian Hills, TX2,779 people · 4 mi NE
- Heidelberg, TX2,221 people · 5 mi E
- Llano Grande, TX2,195 people · 3 mi S
- Bluetown, TX688 people · 12 mi SE
- Santa Maria, TX600 people · 10 mi SE
- Bixby, TX448 people · 8 mi E
- Progreso Lakes, TX275 people · 8 mi S
- Villa Verde, TX228 people · 4 mi SW
- Relampago, TX171 people · 8 mi SE
- Iglesia Antigua, TX129 people · 11 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Weslaco's climate
What is the coldest month in Weslaco?
January, with a normal high of 71°F and a normal low of 50°F. The warmest is August (97°F by day, 76°F at night).
What is the rainiest month in Weslaco?
September, with 5.64 in of precipitation in a normal year; the driest is February with 0.95 in.
What plant hardiness zone is Weslaco in?
The USDA's 2023 map puts Weslaco in zone 10a across its 2 ZIP code areas (10a in 78596, the largest).
Nearby and next
- Texas climateThe statewide normals and every place in the state
- Santa Rosa, TX9 miles from this station, 74.7°F a year
- Edinburg, TX14 miles from this station, 75.0°F a year
- McAllen, TX17 miles from this station, 77.4°F a year
- Harlingen, TX20 miles from this station, 74.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made