Photo: Jouaienttoi · CC BY-SA 4.0San Antonio reaches 100° on about 18 days a year, more than 94% of U.S. towns
A typical July afternoon reaches 95°, a January night drops to 41°, and snow is almost unheard of.
A year in San Antonio at a glance
Each month’s typical high and low, and what it brings.
What stands out about San Antonio’s climate
Compared with towns across the U.S., with San Antonio’s place in Texas beside it.
What a year in San Antonio feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 277 frost-free days a year
In half of years the last 32° night comes by February 26 and the first by November 28. Frost and day counts come from NOAA’s station at San Antonio International Airport, 6 miles from the city’s center point, at about the same height.
The 2023 USDA map puts San Antonio’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 23°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 32 inches of rain a year
May is the wettest month and February the driest. Rain falls on about 81 days a year. Snow is rare: about 0.2" in a normal year at San Antonio International Airport, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in San Antonio
31% of the work is heating, so air conditioning is the bigger bill. Months averaging under 55°: December and January.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at San Antonio International Airport.
Living with San Antonio’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
277 frost-free days in zone 9a. The last frost comes by Feb 26 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 28.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, October, November and December. 342 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in San Antonio from natural hazards, river flooding is the largest share (59%); heat waves, cold waves, winter storms and ice storms together are 8%. Normals are averages; the hazards page covers the extremes.
Natural hazards →San Antonio and its neighbors
Fair Oaks Ranch has the coldest January nights next door (39°, 2° colder) and Von Ormy the hottest July afternoons (97°, 1° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like San Antonio’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| San Antonio, TX | 41° | 95° | 32" | 0.2" |
| Chico, CA | 38° | 96° | 31" | 0.0" |
| Lawton, OK | 29° | 96° | 32" | 1.8" |
| Grants Pass, OR | 34° | 90° | 33" | 0.9" |
| Cayce, SC | 35° | 93° | 46" | 1.2" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in San Antonio averaged 1.0° warmer than the 1900s. The biggest change is in February (+1.9°).
A smaller shift than in 80% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods. In a city of 1.5 million, part of the change is the city itself: pavement and buildings hold heat (the urban heat island).
How San Antonio compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with San Antonio’s place among Texas’.
San Antonio weather by month
Highs, lows and precipitation from NOAA’s grid at San Antonio’s center; snow, wet days and snow on the ground from San Antonio International Airport. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 64° | 41° | 1.9" | 0.0" | 7 | 0 | 48° – 58° |
| February | 68° | 45° | 1.8" | 0.1" | 7 | 0 | 49° – 64° |
| March | 74° | 52° | 2.4" | 0.0" | 9 | 0 | 57° – 68° |
| April | 81° | 58° | 2.4" | 0.0" | 6 | 0 | 64° – 76° |
| May | 87° | 66° | 4.0" | 0.0" | 8 | 0 | 72° – 80° |
| June | 93° | 72° | 3.4" | 0.0" | 7 | 0 | 79° – 86° |
| July | 95° | 74° | 2.3" | 0.0" | 5 | 0 | 80° – 88° |
| August | 97° | 74° | 2.4" | 0.0" | 5 | 0 | 81° – 89° |
| September | 91° | 69° | 3.6" | 0.0" | 7 | 0 | 76° – 85° |
| October | 83° | 60° | 3.4" | 0.0" | 6 | 0 | 68° – 76° |
| November | 72° | 50° | 2.2" | 0.0" | 6 | 0 | 56° – 67° |
| December | 65° | 42° | 1.9" | 0.1" | 7 | 0 | 47° – 57° |
| Year | 81° | 58° | 31.6" | 0.2" | 81 | 0 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 49° to 64°. June is the most reliable, staying within 8°.
Where San Antonio’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at San Antonio’s center.
- Snow: San Antonio International Airport (the official station).
- Frost, freezing nights, 90° and 100° days, heating and cooling: San Antonio International Airport, 6 miles from the city’s center point, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about San Antonio’s climate
What is the weather like in San Antonio?
A typical July afternoon reaches 95°, a January night drops to 41°, and snow is almost unheard of. Milder January nights than 90% of U.S. towns; hotter July afternoons than 96% of U.S. towns.
How cold does it get in San Antonio in winter?
January nights average 41°. About 14 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 48°.
How much snow does San Antonio get?
About 0.2 inches in a normal winter at San Antonio International Airport, so most winters see none.
How hot does it get in San Antonio?
July, with a typical high of 95° and a low of 74°. About 122 days a year reach 90° and 18 reach 100° (San Antonio International Airport).
When is the first and last frost in San Antonio?
In half of years the last spring frost (32°) comes by February 26 and the first fall frost by November 28, about 277 frost-free days, at San Antonio International Airport.
What growing zone is San Antonio in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 23°.
What is the best time of year to visit San Antonio?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is San Antonio getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 80% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in San Antonio.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.