San Antonio Heat Breaks, But High Pressure Returns

San Antonio's weather experienced a dramatic shift with destructive storms on Friday, concluding a significant heatwave that saw temperatures soar to 100 degrees. As of Monday, August 31, 2026, a high-pressure system is regaining control over South Texas, promising a return to hot and dry conditions. Forecasters anticipate daytime highs in the mid- to upper 90s, reaching around 100 degrees on Monday, with the heat index potentially reaching 102 due to humidity. Overnight temperatures will remain above 76 degrees. Tuesday and Wednesday are expected to be sunny and hot, with highs near 98 and 99 degrees respectively, under southeasterly winds carrying moisture from the Gulf.

While a tropical low-pressure system is moving through the northern Gulf of Mexico, rain chances for San Antonio remain slight, mainly impacting the Coastal Plains east of the I-35 corridor on Tuesday and Wednesday. A low-pressure trough may move inland, but with limited support, significant rainfall is unlikely. By Thursday, San Antonio has a 20% chance of afternoon showers and storms, with temperatures peaking around 99 degrees. This chance of precipitation is expected to continue into Friday. Forecasters remain optimistic about a potential pattern shift towards more active, rain-friendly weather by the following weekend.