San Antonio saw clear or mostly clear skies and generally cool conditions Thursday morning, but the city is headed for another round of summerlike heat. Afternoon temperatures will climb to about 91 degrees, with light northeast winds and virtually no chance of rain.
Sunny and Hot Through Sunday
Thursday and Friday will bring nearly identical weather, with sunny skies and highs near 91. Northeast winds will generally stay between 5 and 10 mph, keeping conditions dry and comfortable by South Texas standards.
Temperatures ease slightly Saturday, when the high should reach around 89 under sunny skies. Nights will remain mild, with lows near 69 Thursday and 67 Friday and around 70 Saturday.
Humidity Returns Early Next Week
Sunday is expected to stay generally sunny as southeast or onshore flow returns. That shift in wind direction will begin bringing more moisture back into the area, although rain chances remain very low through the weekend.
Low-end rain chances return early next week. Rising humidity could push heat indexes above 100 degrees in many areas during at least the first half of next week, the National Weather Service says.
The heat index is considered alongside air temperature and relative humidity.
Long-Term Heat Trends
For the San Antonio region, the City of San Antonio’s 2016 Climate Vulnerability Assessment reported that seasonal average summer temperatures increased 0.5°F per decade from 1960–2014. That finding concerns average summer temperatures, not a count of extreme-heat days, and does not by itself explain this weekend’s forecast.
Annual days topping 80, 90 and 100 degrees are another measure, distinct from average summer temperatures. Long-term projections consider changes in the frequency of historically hot days and warm nights; those findings do not predict any particular week’s weather.
No watches, warnings or advisories are in effect for the San Antonio area.
