San Antonio Kelly Air Force Base, Texas climate: Climate normals at a NOAA weather station
San Antonio Kelly Air Force Base's normal year runs from 41°F January nights to 97°F August afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 21.1°C, January lows of 5°C, August highs of 36°C.
- NOAA stationSan Antonio Kelly Air Force Base
- Station IDUSW00012909
- Location29.38°N 98.58°W
- Elevation682 ft (208 m)
On October 23, the normal high in San Antonio Kelly Air Force Base is 82°F and the normal low 57°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for San Antonio Kelly Air Force Base.
- Jan 64° 41°
- Feb 70° 44°
- Mar 75° 52°
- Apr 82° 59°
- May 89° 66°
- Jun 93° 72°
- Jul 96° 74°
- Aug 97° 74°
- Sep 92° 70°
- Oct 84° 60°
- Nov 72° 49°
- Dec 65° 41°
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 San Antonio Kelly Air Force Base each month?
August is the warmest month, with normal highs of 97°F; January the coldest, with normal lows of 41°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 64°F | 41°F | 52.6°F | – | <1 | 4 | 10 h 30 min |
| February | 70°F | 44°F | 56.8°F | – | <1 | 2 | 11 h 10 min |
| March | 75°F | 52°F | 63.6°F | – | 2 | 1 | 12 h |
| April | 82°F | 59°F | 70.2°F | – | 6 | <1 | 12 h 50 min |
| May | 89°F | 66°F | 77.5°F | – | 14 | <1 | 13 h 40 min |
| June | 93°F | 72°F | 82.4°F | – | 24 | <1 | 14 h |
| July | 96°F | 74°F | 84.9°F | – | 31 | <1 | 13 h 50 min |
| August | 97°F | 74°F | 85.5°F | – | 31 | <1 | 13 h 10 min |
| September | 92°F | 70°F | 80.7°F | – | 23 | <1 | 12 h 20 min |
| October | 84°F | 60°F | 72.3°F | – | 12 | <1 | 11 h 30 min |
| November | 72°F | 49°F | 60.4°F | – | <1 | 3 | 10 h 40 min |
| December | 65°F | 41°F | 53.2°F | – | <1 | 5 | 10 h 20 min |
| Year (annual) | 82°F | 59°F | 70.0°F | – | 141 | 14 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 18°C | 5°C | 11.4°C |
| February | 21°C | 7°C | 13.8°C |
| March | 24°C | 11°C | 17.6°C |
| April | 28°C | 15°C | 21.2°C |
| May | 31°C | 19°C | 25.3°C |
| June | 34°C | 22°C | 28.0°C |
| July | 36°C | 23°C | 29.4°C |
| August | 36°C | 23°C | 29.7°C |
| September | 33°C | 21°C | 27.1°C |
| October | 29°C | 16°C | 22.4°C |
| November | 22°C | 9°C | 15.8°C |
| December | 18°C | 5°C | 11.8°C |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00012909; 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 San Antonio Kelly Air Force Base?
Normal highs sit between 65°F and 85°F in February, March, April, October, 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 USW00012909.
When is the last frost at San Antonio Kelly Air Force Base?
In San Antonio Kelly Air Force Base, the last spring frost (32°F) comes after February 22 in half of years and after March 12 in one year in ten; the first autumn frost comes before December 2 in half of years and before November 13 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 12; 9 in 10 after January 16
- First autumn frost, half of years before
- December 21 year in 10 before November 13; 9 in 10 before December 25
NOAA puts the median frost-free season at 284 days, and the season without a hard freeze (28°F) at 322 days.
A hard freeze (28°F) comes after February 1 in half of springs and before December 16 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts San Antonio Kelly Air Force Base in zone 9a in ZIP code 78226, 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 USW00012909; 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 San Antonio Kelly Air Force Base?
In a normal year in San Antonio Kelly Air Force Base, 141 days a year reach 90°F (31 of them 100°F or more) and 14 nights fall to 32°F or colder.
- Days at 90°F or more
- 141a normal year
- Days at 100°F or more
- 31a normal year
- Nights at 32°F or colder
- 14a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
The highest temperature in this station's record (since 1949) is 109°F, on August 21, 2024; the lowest is 4°F, on January 31, 1949.
The wettest calendar year on that record is 1957, with 41.91 in; the snowiest season is 1965–66, with 2.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00012909; records: ACIS (NOAA Regional Climate Centers), station USW00012909. Records use complete months only; a month missing more than three days is left out.
How humid and windy is it at San Antonio Kelly Air Force Base, and how clear are the skies?
The summer (June-August) dew point averages 70°F. The muggiest month is June, with an average dew point of 71°F, above the 65°F at which most people call the air sticky; the driest air comes in December (40°F). April is the windiest month (9.3 mph on average), and September has the most clear or nearly clear hours (61%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 42°F | 64% | 44% | 7.3 mph | 47% | 30% |
| February | 46°F | 63% | 43% | 8.2 mph | 47% | 28% |
| March | 55°F | 67% | 47% | 8.8 mph | 43% | 30% |
| April | 61°F | 66% | 44% | 9.3 mph | 44% | 25% |
| May | 69°F | 70% | 48% | 8.5 mph | 44% | 12% |
| June | 71°F | 68% | 46% | 8.3 mph | 51% | 7% |
| July | 70°F | 63% | 39% | 7.5 mph | 57% | 4% |
| August | 69°F | 64% | 41% | 6.8 mph | 54% | 6% |
| September | 62°F | 65% | 41% | 6.7 mph | 61% | 6% |
| October | 54°F | 67% | 44% | 7.2 mph | 53% | 17% |
| November | 45°F | 67% | 45% | 6.8 mph | 52% | 22% |
| December | 40°F | 65% | 45% | 7.0 mph | 51% | 26% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00012909. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is it at San Antonio Kelly Air Force Base?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds at San Antonio Kelly Air Force Base, 4.8 kWh per square metre a day. August is the sunniest month (88%) and February the cloudiest (69%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 72% | 3.1 |
| February | 69% | 3.6 |
| March | 71% | 4.5 |
| April | 74% | 5.4 |
| May | 76% | 5.8 |
| June | 84% | 6.7 |
| July | 86% | 6.7 |
| August | 88% | 6.4 |
| September | 81% | 5.2 |
| October | 81% | 4.4 |
| November | 76% | 3.3 |
| December | 72% | 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 San Antonio Kelly Air Force Base record?
A normal year at San Antonio Kelly Air Force Base brings 1,312 heating degree days, 76% fewer than the median U.S. place (5,373), and 3,155 cooling degree days, 3.5 times the median (908). Two months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 7,412 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 386 | 1 |
| February | 240 | 9 |
| March | 108 | 63 |
| April | 11 | 167 |
| May | 0 | 386 |
| June | 0 | 522 |
| July | 0 | 615 |
| August | 0 | 635 |
| September | 0 | 471 |
| October | 14 | 240 |
| November | 185 | 47 |
| December | 369 | 2 |
| Year (annual) | 1,312 | 3,155 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00012909. 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 San Antonio Kelly Air Force Base been warmer than normal?
2025 averaged 73.6°F, 3.6°F above the 1991-2020 normal of 70.0°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal |
|---|---|---|
| 2021 | 70.2°F | +0.2°F |
| 2022 | 70.8°F | +0.8°F |
| 2023 | 72.2°F | +2.2°F |
| 2024 | 74.1°F | +4.1°F |
| 2025 | 73.6°F | +3.6°F |
Over 53 complete years from 1949 to 2025, the station's annual mean temperature rose at a fitted 3.4°F per century (+0.19°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00012909; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does San Antonio Kelly Air Force Base's climate compare?
San Antonio Kelly Air Force Base is warmer than 257 of the 321 places with their own NOAA record in Texas. Across the 7,247 U.S. stations with normals, its annual mean of 70.0°F is warmer than 95%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near San Antonio Kelly Air Force Base share this climate record?
3 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.
- Lackland AFB, TX6,650 people · 2 mi W
- Von Ormy, TX1,215 people · 9 mi SW
- Macdona, TX449 people · 8 mi SW
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 San Antonio Kelly Air Force Base's climate
What is the coldest month at San Antonio Kelly Air Force Base?
January, with a normal high of 64°F and a normal low of 41°F. The warmest is August (97°F by day, 74°F at night).
What plant hardiness zone is San Antonio Kelly Air Force Base in?
The USDA's 2023 map puts San Antonio Kelly Air Force Base in zone 9a in ZIP code 78226, the nearest ZIP area.
How late can frost come at San Antonio Kelly Air Force Base?
In half of years the last 32°F night comes after February 22; in one year in ten it comes after March 12. Waiting until March 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Texas climateThe statewide normals and every place in the state
- San Antonio/Seaworld, TX9 miles from this station, 71.2°F a year
- San Antonio Incarnate Word, TX9 miles from this station, 69.0°F a year
- San Antonio, TX12 miles from this station, 69.6°F a year
- Lytle, TX19 miles from this station, 70.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made