Forecast for San Antonio, Texas, on Thursday, June 12
The weather in San Antonio for Thursday, June 12, 2025, will remain unstable due to the influence of humid subtropical air masses coming from the Gulf of Mexico, bringing the risk of showers and thunderstorms throughout the day.
During the morning hours, there is a moderate chance (around 60%) of scattered rain showers, especially before 1:00 p.m. CDT. After that, from 1:00 p.m. to 4:00 p.m., conditions could worsen, with the likelihood of isolated thunderstorms that may bring brief heavy rain and gusty winds.
Temperature overview: mild overnight, hot afternoon
Minimum temperatures tonight will drop to around 73°F (23°C) under mostly cloudy skies. Winds will come from the south-southeast at 5 to 10 mph, maintaining a humid and warm overnight feel.
Tomorrow afternoon, expect maximum temperatures near 87°F (31°C), although high humidity will make it feel warmer. Skies will remain mostly overcast during the day, with short breaks of sun possible during early afternoon.
UV index and cloud cover
Despite cloudy conditions, the UV index is forecasted to be moderate to high, especially during mid-morning and early afternoon. This means short-term sun exposure may still cause skin irritation. Cloud coverage will likely stay above 70% throughout the day, but will vary in density depending on the movement of convective cells linked to potential thunderstorms.
Climatic context of San Antonio
San Antonio, located in south-central Texas, typically experiences a semi-arid to humid subtropical climate, depending on the season. June usually marks the beginning of a transition into the hot season, with frequent storm activity caused by tropical moisture rising from the south. These thunderstorms are often brief but intense, especially during the afternoon and evening hours.
For Thursday, expect this climatic variability to manifest with intermittent rain, thunder, and humid heat, typical of early summer across much of Texas.
