San Antonio, Texas, has a humid subtropical climate, meaning its winters are generally mild and brief. While the sight of snowflakes is a rare event, snow is not an impossible occurrence. The city’s southern geographical location means frozen precipitation is an anomaly, happening only when specific atmospheric conditions align. The infrequency of snowfall is directly tied to its geographical location.
The Meteorological Factors Limiting Snowfall
San Antonio’s latitude places it too far south for consistent, prolonged exposure to the frigid air masses needed for snow. The primary limiting factor is the city’s proximity to the Gulf of Mexico, which is only about 140 miles away. This warm body of water acts as a temperature moderator, injecting moisture into the atmosphere that generally keeps winter temperatures too high for precipitation to freeze all the way to the ground.
The necessary combination of freezing temperatures and sufficient moisture rarely occurs simultaneously. When a powerful cold front, known as a “Blue Norther,” plunges south, it typically scours the moisture out of the air, resulting in clear, dry, and cold conditions. Conversely, a moisture-rich system arriving from the Gulf usually finds that the ground temperatures are above freezing, causing the precipitation to fall as rain instead of snow.
Statistical Frequency and Typical Accumulation
Measurable snowfall, defined as 0.1 inch or more, is a relatively infrequent event in San Antonio’s climate history. On average, the city receives measurable snow only once every three to four years. The actual annual average accumulation is near zero or just a trace amount, highlighting the unpredictable nature of winter weather in the region.
When snow does accumulate, it is usually a light dusting that quickly melts away, often lasting only a few hours. A more significant snowfall event, where two to four inches of accumulation are recorded, is even rarer, typically occurring only about once every ten years. San Antonio has experienced extended snow-free streaks, such as a fifteen-year period between 1988 and 2003.
Records of Major Snow Events
Despite the statistical rarity, San Antonio has occasionally been struck by memorable, heavy snowfalls that stand as historical anomalies. The record for the city’s heaviest one-day snowfall occurred on January 12, 1985, when a powerful winter storm dropped 13.2 inches of snow. This single event accounted for the majority of the city’s snowiest year on record, with 15.9 inches accumulating throughout 1985.
More recently, the February 2021 winter storm brought a significant and impactful snow and ice event. Over a period of several days, the city recorded a total accumulation of 6.2 inches of snow. This event was particularly notable for the prolonged period of below-freezing temperatures, which caused widespread power outages and infrastructure issues. Before these events, a historic storm in 1926 delivered 6.4 inches over two days.