San Antonio, Texas, experiences a humid subtropical climate that shapes daily life and seasonal rhythms across the city. Understanding the average temperatures here helps residents and visitors plan activities, choose clothing, and manage energy use throughout the year. This overview breaks down the data in a clear, practical way.
Year-Round Temperature Patterns
The city sees long, hot summers and mild winters, with relatively small temperature swings between seasons compared to northern locations. Average conditions are influenced by proximity to the Gulf of Mexico, elevation, and occasional cold fronts. Looking at monthly averages reveals a gradual rise in heat from spring, a prolonged summer plateau, and a gentle cooldown into early winter.
Summer Heat and Humidity
June Through August
During peak summer, average high temperatures typically reach the mid to upper 90s Fahrenheit, often climbing above 100 degrees during heat waves. Nighttime lows usually stay in the mid 70s, providing little relief from the overall warmth. Combined with moderate to high humidity, these conditions create a distinctly sultry atmosphere.
June averages: High near 94°F, Low near 74°F
July averages: High near 97°F, Low near 76°F
August averages: High near 96°F, Low near 75°F
Transition Seasons
Spring and Fall
Spring and fall act as comfortable buffers, with moderate temperatures and lower humidity making outdoor activities especially pleasant. These seasons feature more variable weather, as cold fronts can briefly interrupt warming trends in spring and extend warmth into fall.
March averages: High near 71°F, Low near 50°F
April averages: High near 79°F, Low near 58°F
October averages: High near 83°F, Low near 62°F
November averages: High near 72°F, Low near 51°F
Winter Coolness and Rare Extremes
December Through February
Winters in San Antonio are generally mild, but cold snaps can bring temperatures below freezing for short periods. Average conditions remain comfortable for most of the season, with occasional dips that affect sensitive plants and outdoor plans.
December averages: High near 61°F, Low near 42°F
January averages: High near 63°F, Low near 44°F
February averages: High near 67°F, Low near 47°F
Monthly Temperature Range Overview
Across the calendar year, the difference between the coolest and warmest average days can span more than 40 degrees, highlighting the shift from winter comfort to intense summer heat. This range reflects both latitude and local geography, including river corridors and urban heat effects.
