San Antonio/Seaworld, Texas climate: Climate normals at a NOAA weather station
San Antonio/Seaworld's normal year runs from 43°F January nights to 99°F August afternoons, with 31.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 21.8°C, January lows of 6°C, August highs of 37°C, 803 mm of precipitation a year.
- NOAA stationSan Antonio/Seaworld
- Station IDUSC00418169
- Location29.45°N 98.70°W
- Elevation940 ft (287 m)
On October 23, the normal high in San Antonio/Seaworld is 83°F and the normal low 59°F, and the chance of measurable rain or snow is 18%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for San Antonio/Seaworld.
- Jan 65° 43°
- Feb 70° 46°
- Mar 76° 53°
- Apr 83° 60°
- May 89° 67°
- Jun 95° 73°
- Jul 97° 74°
- Aug 99° 74°
- Sep 93° 70°
- Oct 85° 62°
- Nov 74° 51°
- Dec 66° 44°
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/Seaworld each month?
August is the warmest month, with normal highs of 99°F; January the coldest, with normal lows of 43°F. The most precipitation falls in May (4.02 in), the least in February (1.84 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 65°F | 43°F | 53.9°F | 2.01 | 8 | <1 | 4 | 10 h 30 min |
| February | 70°F | 46°F | 58.0°F | 1.84 | 7 | <1 | 3 | 11 h 10 min |
| March | 76°F | 53°F | 64.5°F | 2.30 | 8 | 1 | 2 | 12 h |
| April | 83°F | 60°F | 71.4°F | 2.43 | 6 | 4 | <1 | 12 h 50 min |
| May | 89°F | 67°F | 78.1°F | 4.02 | 7 | 13 | <1 | 13 h 40 min |
| June | 95°F | 73°F | 83.7°F | 3.40 | 6 | 23 | <1 | 14 h |
| July | 97°F | 74°F | 85.8°F | 2.35 | 5 | 28 | <1 | 13 h 50 min |
| August | 99°F | 74°F | 86.4°F | 2.52 | 4 | 29 | <1 | 13 h 10 min |
| September | 93°F | 70°F | 81.4°F | 3.14 | 7 | 19 | <1 | 12 h 20 min |
| October | 85°F | 62°F | 73.1°F | 3.81 | 5 | 6 | <1 | 11 h 30 min |
| November | 74°F | 51°F | 62.7°F | 1.90 | 5 | <1 | 1 | 10 h 40 min |
| December | 66°F | 44°F | 55.0°F | 1.89 | 7 | <1 | 4 | 10 h 20 min |
| Year (annual) | 83°F | 60°F | 71.2°F | 31.61 | 76 | 123 | 14 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 18°C | 6°C | 12.2°C | 51 mm |
| February | 21°C | 8°C | 14.4°C | 47 mm |
| March | 24°C | 12°C | 18.1°C | 58 mm |
| April | 29°C | 15°C | 21.9°C | 62 mm |
| May | 32°C | 19°C | 25.6°C | 102 mm |
| June | 35°C | 23°C | 28.7°C | 86 mm |
| July | 36°C | 24°C | 29.9°C | 60 mm |
| August | 37°C | 24°C | 30.2°C | 64 mm |
| September | 34°C | 21°C | 27.4°C | 80 mm |
| October | 29°C | 17°C | 22.8°C | 97 mm |
| November | 24°C | 11°C | 17.1°C | 48 mm |
| December | 19°C | 7°C | 12.8°C | 48 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00418169; 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/Seaworld?
Normal highs sit between 65°F and 85°F in January, February, March, April, October, November and December. Of those, November has the fewest days with rain (5).
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 USC00418169.
When is the last frost at San Antonio/Seaworld?
In San Antonio/Seaworld, the last spring frost (32°F) comes after February 18 in half of years and after March 16 in one year in ten; the first autumn frost comes before December 9 in half of years and before November 17 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 181 year in 10 after March 16; 9 in 10 after January 18
- First autumn frost, half of years before
- December 91 year in 10 before November 17; 9 in 10 before January 13
NOAA puts the median frost-free season at 296 days, and the season without a hard freeze (28°F) at 334 days.
A hard freeze (28°F) comes after January 31 in half of springs and before December 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts San Antonio/Seaworld in zone 9a in ZIP code 78251, 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 USC00418169; 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/Seaworld?
In a normal year in San Antonio/Seaworld, 123 days a year reach 90°F (21 of them 100°F or more), 14 nights fall to 32°F or colder and 76 days bring measurable precipitation.
- Days at 90°F or more
- 123a normal year
- Days at 100°F or more
- 21a normal year
- Nights at 32°F or colder
- 14a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 76a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00418169.
How sunny is it at San Antonio/Seaworld?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds at San Antonio/Seaworld, 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/Seaworld record?
A normal year at San Antonio/Seaworld brings 1,182 heating degree days, 78% fewer than the median U.S. place (5,373), and 3,460 cooling degree days, 3.8 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 7,892 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 353 | 7 |
| February | 224 | 29 |
| March | 106 | 89 |
| April | 20 | 212 |
| May | 1 | 407 |
| June | 0 | 561 |
| July | 0 | 643 |
| August | 0 | 665 |
| September | 1 | 495 |
| October | 18 | 269 |
| November | 138 | 69 |
| December | 323 | 15 |
| Year (annual) | 1,182 | 3,460 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00418169. 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.
How does San Antonio/Seaworld's climate compare?
San Antonio/Seaworld is warmer than 280 of the 321 places with their own NOAA record in Texas, and wetter than 163. Across the 7,247 U.S. stations with normals, its annual mean of 71.2°F is warmer than 96%.
In the Köppen classification computed from these normals, San Antonio/Seaworld 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 San Antonio/Seaworld 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.
- Leon Valley, TX11,424 people · 6 mi NE
- Helotes, TX10,223 people · 9 mi N
- Grey Forest, TX517 people · 11 mi N
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/Seaworld's climate
What is the coldest month at San Antonio/Seaworld?
January, with a normal high of 65°F and a normal low of 43°F. The warmest is August (99°F by day, 74°F at night).
Does it snow at San Antonio/Seaworld?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month at San Antonio/Seaworld?
May, with 4.02 in of precipitation in a normal year; the driest is February with 1.84 in.
What plant hardiness zone is San Antonio/Seaworld in?
The USDA's 2023 map puts San Antonio/Seaworld in zone 9a in ZIP code 78251, the nearest ZIP area.
How late can frost come at San Antonio/Seaworld?
In half of years the last 32°F night comes after February 18; in one year in ten it comes after March 16. Waiting until March 16 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 Kelly Air Force Base, TX9 miles from this station, 70.0°F a year
- San Antonio Incarnate Word, TX14 miles from this station, 69.0°F a year
- San Antonio, TX15 miles from this station, 69.6°F a year
- Lytle, TX17 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