Armstrong (4 mi SE), Texas climate: Climate normals at a NOAA weather station
Armstrong (4 mi SE)'s normal year runs from 45°F January nights to 98°F August afternoons, with 28.1 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 22.9°C, January lows of 7°C, August highs of 36°C, 712 mm of precipitation a year.
- NOAA stationArmstrong (4 mi SE)
- Station IDUSC00410345
- Location26.83°N 97.71°W
- Elevation25 ft (8 m)
On October 22, the normal high in Armstrong (4 mi SE) is 86°F and the normal low 60°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Armstrong (4 mi SE).
- Jan 70° 45°
- Feb 75° 50°
- Mar 80° 55°
- Apr 86° 61°
- May 91° 69°
- Jun 96° 72°
- Jul 96° 73°
- Aug 98° 73°
- Sep 94° 70°
- Oct 88° 62°
- Nov 79° 54°
- Dec 73° 48°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Armstrong (4 mi SE) each month?
August is the warmest month, with normal highs of 98°F; January the coldest, with normal lows of 45°F. The most precipitation falls in September (5.16 in), the least in January (1.06 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 70°F | 45°F | 57.3°F | 1.06 | – | <1 | 4 | 10 h 40 min |
| February | 75°F | 50°F | 62.3°F | 1.34 | – | 2 | 3 | 11 h 10 min |
| March | 80°F | 55°F | 67.3°F | 1.30 | – | 4 | 1 | 12 h |
| April | 86°F | 61°F | 73.8°F | 1.47 | – | 11 | <1 | 12 h 50 min |
| May | 91°F | 69°F | 79.8°F | 2.85 | – | 21 | <1 | 13 h 30 min |
| June | 96°F | 72°F | 84.1°F | 3.23 | – | 28 | <1 | 13 h 50 min |
| July | 96°F | 73°F | 84.7°F | 2.53 | – | 29 | <1 | 13 h 40 min |
| August | 98°F | 73°F | 85.3°F | 2.53 | – | 30 | <1 | 13 h 10 min |
| September | 94°F | 70°F | 81.8°F | 5.16 | – | 24 | <1 | 12 h 20 min |
| October | 88°F | 62°F | 75.2°F | 3.33 | – | 17 | <1 | 11 h 30 min |
| November | 79°F | 54°F | 66.3°F | 1.96 | – | 3 | 1 | 10 h 50 min |
| December | 73°F | 48°F | 60.3°F | 1.29 | – | <1 | 3 | 10 h 30 min |
| Year (annual) | 85°F | 61°F | 73.2°F | 28.05 | – | 169 | 11 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 21°C | 7°C | 14.1°C | 27 mm |
| February | 24°C | 10°C | 16.8°C | 34 mm |
| March | 26°C | 13°C | 19.6°C | 33 mm |
| April | 30°C | 16°C | 23.2°C | 37 mm |
| May | 33°C | 20°C | 26.6°C | 72 mm |
| June | 35°C | 22°C | 28.9°C | 82 mm |
| July | 36°C | 23°C | 29.3°C | 64 mm |
| August | 36°C | 23°C | 29.6°C | 64 mm |
| September | 34°C | 21°C | 27.7°C | 131 mm |
| October | 31°C | 17°C | 24.0°C | 85 mm |
| November | 26°C | 12°C | 19.1°C | 50 mm |
| December | 23°C | 9°C | 15.7°C | 33 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00410345; 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.
Which months are mildest at Armstrong (4 mi SE)?
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 USC00410345.
When is the last frost at Armstrong (4 mi SE)?
In Armstrong (4 mi SE), the last spring frost (32°F) comes after February 22 in half of years and after March 14 in one year in ten; the first autumn frost comes before December 5 in half of years and before November 15 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- February 221 year in 10 after March 14; 9 in 10 after January 19
- First autumn frost, half of years before
- December 51 year in 10 before November 15; 9 in 10 before January 6
NOAA puts the median frost-free season at 293 days, and the season without a hard freeze (28°F) at 331 days.
A hard freeze (28°F) comes after January 31 in half of springs and before December 22 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Armstrong (4 mi SE) in zone 9b in ZIP code 78338, the nearest ZIP area.
Frost dates for every NOAA station in Texas · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00410345; 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.
How hot and how cold does it get at Armstrong (4 mi SE)?
In a normal year in Armstrong (4 mi SE), 169 days a year reach 90°F (31 of them 100°F or more) and 11 nights fall to 32°F or colder.
- Days at 90°F or more
- 169a normal year
- Days at 100°F or more
- 31a normal year
- Nights at 32°F or colder
- 11a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00410345.
How sunny is it at Armstrong (4 mi SE)?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds at Armstrong (4 mi SE), 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 many heating and cooling degree days does Armstrong (4 mi SE) record?
A normal year at Armstrong (4 mi SE) brings 853 heating degree days, 84% fewer than the median U.S. place (5,373), and 3,861 cooling degree days, 4.3 times the median (908). No month reaches 300 heating degree days. For gardens and crops, NOAA counts 8,573 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 276 | 38 |
| February | 156 | 81 |
| March | 84 | 156 |
| April | 15 | 278 |
| May | 1 | 460 |
| June | 0 | 571 |
| July | 0 | 612 |
| August | 0 | 629 |
| September | 0 | 505 |
| October | 10 | 325 |
| November | 93 | 133 |
| December | 217 | 72 |
| Year (annual) | 853 | 3,861 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00410345. 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.
Have recent years at Armstrong (4 mi SE) been warmer than normal?
2023 averaged 75.0°F, 1.8°F above the 1991-2020 normal of 73.2°F.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2023 | 75.0°F | +1.8°F | 21.59 |
Source: observed years: ACIS, station USC00410345. A year counts only with all twelve months complete.
How does Armstrong (4 mi SE)'s climate compare?
Armstrong (4 mi SE) is warmer than 304 of the 321 places with their own NOAA record in Texas, and wetter than 137. Across the 7,247 U.S. stations with normals, its annual mean of 73.2°F is warmer than 98%.
In the Köppen classification computed from these normals, Armstrong (4 mi SE) 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.
Questions about Armstrong (4 mi SE)'s climate
What is the coldest month at Armstrong (4 mi SE)?
January, with a normal high of 70°F and a normal low of 45°F. The warmest is August (98°F by day, 73°F at night).
What is the rainiest month at Armstrong (4 mi SE)?
September, with 5.16 in of precipitation in a normal year; the driest is January with 1.06 in.
What plant hardiness zone is Armstrong (4 mi SE) in?
The USDA's 2023 map puts Armstrong (4 mi SE) in zone 9b in ZIP code 78338, the nearest ZIP area.
How late can frost come at Armstrong (4 mi SE)?
In half of years the last 32°F night comes after February 22; in one year in ten it comes after March 14. Waiting until March 14 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Texas climateThe statewide normals and every place in the state
- Port Mansfield, TX26 miles from this station, 73.4°F a year
- Raymondville, TX26 miles from this station, 74.4°F a year
- Sarita, TX27 miles from this station, 72.1°F a year
- McCook, TX32 miles from this station, 73.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made