San Antonio climate
San Antonio (Texas, United States) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 21 °C70 °F, and about 780 mm31 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
San Antonio climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 1763 | 540 | 1151 | 491.9 | 5 |
| Feb | 2068 | 644 | 1356 | 361.4 | 3 |
| Mar | 2476 | 1151 | 1763 | 622.4 | 1 |
| Apr | 2984 | 1559 | 2271 | 622.5 | 0 |
| May | 3289 | 1967 | 2678 | 1003.9 | 0 |
| Jun | 3595 | 2373 | 2984 | 712.8 | 0 |
| Jul | 3696 | 2475 | 3085 | 712.8 | 0 |
| Aug | 3697 | 2476 | 3087 | 622.4 | 0 |
| Sep | 3290 | 2170 | 2780 | 953.8 | 0 |
| Oct | 2883 | 1660 | 2272 | 793.1 | 0 |
| Nov | 2373 | 1050 | 1661 | 491.9 | 1 |
| Dec | 1864 | 542 | 1253 | 451.8 | 4 |
| Year | 3697 | 540 | 2170 | 78031 | 13 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 70% | 55% | 3.1 | 10:27 |
| Feb | 70% | 60% | 3.6 | 11:07 |
| Mar | 70% | 61% | 4.5 | 11:55 |
| Apr | 66% | 60% | 5.4 | 12:51 |
| May | 68% | 60% | 5.9 | 13:37 |
| Jun | 65% | 46% | 6.7 | 14:01 |
| Jul | 65% | 44% | 6.7 | 13:51 |
| Aug | 61% | 41% | 6.4 | 13:12 |
| Sep | 68% | 46% | 5.2 | 12:18 |
| Oct | 68% | 41% | 4.4 | 11:24 |
| Nov | 70% | 50% | 3.3 | 10:38 |
| Dec | 69% | 55% | 2.8 | 10:16 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of San Antonio is like
The warmest month is August, with an average high of 36 °C97 °F and a low of 24 °C76 °F. The coldest is January, when highs average 17 °C63 °F and lows 5 °C40 °F. Seasons are strongly marked: the warmest month is on average 19.5 °C35.1 °F warmer than the coldest.
Annual precipitation is moderate at about 780 mm31 in. The wettest three-month stretch is May–July, which brings 31% of the annual total. The wettest month is May (100 mm3.9 in), the driest is February (36 mm1.4 in).
Relative humidity ranges from 61% in August to 70% in January. The clearest skies (lowest average cloud amount, 41%) are typical of August. Average wind speed near the ground ranges from 9 km/h (5 mph) in September to 12 km/h (7 mph) in April. Daylight lasts from about 10.3 hours in December to 14.0 hours in June.
Best time to visit San Antonio
Based on these averages, the most comfortable months for sightseeing and outdoor activities are February–April and October–December. Average highs then reach 18 °C64 °F to 29 °C84 °F. Precipitation is 36 mm1.4 in to 79 mm3.1 in per month.
The most challenging month is August, which is hot, with average highs of 36 °C97 °F.
Comfort score: months are ranked by how close they come to an ideal. That means an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
San Antonio weather by month
- January17 °C63 °F / 5 °C40 °F
- February20 °C68 °F / 6 °C44 °F
- March24 °C76 °F / 11 °C51 °F
- April29 °C84 °F / 15 °C59 °F
- May32 °C89 °F / 19 °C67 °F
- June35 °C95 °F / 23 °C73 °F
- July36 °C96 °F / 24 °C75 °F
- August36 °C97 °F / 24 °C76 °F
- September32 °C90 °F / 21 °C70 °F
- October28 °C83 °F / 16 °C60 °F
- November23 °C73 °F / 10 °C50 °F
- December18 °C64 °F / 5 °C42 °F
What to pack for San Antonio
- Winter (December–February) — highs 1763 to 20 °C68 °F, lows 540 to 6 °C44 °F, about 43 mm1.7 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
- Spring (March–May) — highs 2476 to 32 °C89 °F, lows 1151 to 19 °C67 °F, about 75 mm2.9 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
- Summer (June–August) — highs 3595 to 36 °C97 °F, lows 2373 to 24 °C76 °F, about 68 mm2.7 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water.
- Autumn (September–November) — highs 2373 to 32 °C90 °F, lows 1050 to 21 °C70 °F, about 74 mm2.9 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
How San Antonio compares
The nearest larger place is Houston, about 305 km to the east. Compared with it, San Antonio is on average 0.5 °C1 °F warmer. It receives 37% less precipitation (780 mm31 in vs 1,247 mm49 in). The difference is largest in April (1.1 °C2 °F warmer).
World Climates covers 222 places in the United States. By annual mean temperature, San Antonio is the 18th warmest of them. By annual precipitation, it is the 145th wettest. See all of them on the United States climate page.
Some places in other countries have a very similar pattern of temperature and rainfall. The closest matches are Muzaffarabad (Pakistan, Cfa), Putian (China, Cfa) and Yizhou (China, Cfa).
Nearby places
- Climate in Austin 118 km · 20 °C69 °F · 840 mm33 in
- Climate in Killeen 202 km · 20 °C67 °F · 831 mm33 in
- Climate in Corpus Christi 210 km · 23 °C73 °F · 718 mm28 in
- Climate in Piedras Negras 213 km · 23 °C73 °F · 477 mm19 in
- Climate in Ciudad Acuña 238 km · 23 °C73 °F · 412 mm16 in
- Climate in Nuevo Laredo 239 km · 24 °C74 °F · 559 mm22 in
- Climate in College Station 247 km · 20 °C68 °F · 1,069 mm42 in
- Climate in Waco 269 km · 20 °C67 °F · 946 mm37 in
Frequently asked questions
What is the warmest month in San Antonio?
August is the warmest month in San Antonio. Its average high is 36 °C (97 °F) and its average low is 24 °C (76 °F).
What is the coldest month in San Antonio?
January is the coldest month. Its average high is 17 °C (63 °F) and its average low is 5 °C (40 °F).
When does it rain the most in San Antonio?
May is the wettest month with about 100 mm (3.9 in) of precipitation. February is the driest with about 36 mm (1.4 in).
What is the best time to visit San Antonio?
Judging by long-term averages, the most comfortable months are February–April and October–December.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station. So they can differ from airport records. The gaps are largest on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 302 m, while San Antonio lies at about 198 m. Temperatures on this page were therefore adjusted by +0.7 °C1.2 °F using the standard lapse rate of 6.5 °C per 1,000 m.