San Antonio’s temperature has mild fluctuations from summer to winter. The two main climate influences are tropical and desert. And because it lies near the western edge of the humid subtropical climate zone, temperatures alternate from dry to humid depending on the winds and the humidity brought on by the Gulf of Mexico.

San Antonio receives about a dozen sub-freezing nights each year and snow itself is very uncommon. According to the National Weather Service, there have only been 31 instances of snowfall in the city in the past 122 years (an average of once every four years).

The warmest months of the year in San Antonio are July and August, with average temperatures of 95 degrees Fahrenheit (35 °C). The highest temperature ever recorded was 111 °F (44 °C) on September 5, 2000. On average, the coolest month of the year is January. The lowest temperature ever recorded was 0 °F (−18 °C) on January 31, 1949.

The all-time annual average temperature is 69.1 degrees – which is one of the main reasons tourists find San Antonio so hard to resist.

Cold fronts from Canada and tropical systems from the gulf bring rain to San Antonio, with most precipitation occurring in the late spring or early fall.

 

Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Average high °F (°C) 62.1 (16.72) 67.1 (19.5) 74.3 (23.5) 80.4 (26.89) 86.0M (30) 91.4 (33) 94.6 (34.78) 94.7 (34.83) 90.0 (32.22) 82.0 (27.78) 71.4 (21.89) 64.0 (17.78)
Average low °F (°C) 38.6 (3.67) 42.4 (5.78) 49.9 (9.94) 56.9 (13.83) 65.5 (18.61) 71.6 (22) 74.0 (23.033) 73.6 (23.11) 68.8 (20.44) 59.4 (15.22) 48.6 (9.22) 40.8 (4.89)
Precipitation inches (mm) 1.66 (42.2) 1.75 (44.4) 1.89 (48) 2.60 (66) 4.72 (119.9) 4.30 (109.2) 2.03 (51.6) 2.57 (65.3) 3.00 (76.2) 3.86 (98) 2.58 (65.5) 1.96 (49.8)
Avg. precipitation days (≥ 0.01 in) 7.6 6.8 7.9 7.3 9.2 7.7 4.6 5.2 6.5 6.9 7.3 7.8
Sunshine hours 158.1 172.3 217.0 210.0 223.2 276.0 310.0 294.5 234.0 217.0 171.0 148.8
Sources: NOAA and The Weather Channel