San Antonio is forecast to reach 89°F on Tuesday, Oct. 6, with sunny skies, according to the National Weather Service. That warm forecast sits near the point in October when the city’s 90-degree days typically wind down—but it is not itself a 90-degree forecast.
Warm weather can extend into October
An Express-News analysis of San Antonio historical records puts the average last 90-degree day at Oct. 12. Since 2000, the average date has been Oct. 18. Those averages show that early- and mid-October heat can fall within the city’s usual 90-degree season; they do not establish how often temperatures reach 88°F on Oct. 6.
The forecast is below the date’s record
The National Weather Service’s San Antonio climate report lists the Oct. 6 record high as 95°F, set in 1931. Tuesday’s forecast is 6 degrees below that mark. A separate NWS climate summary says the city’s average maximum temperature in October 2025 was 88.7°F, 6.5 degrees above the 1991–2020 normal of 82.2°F. That is a monthly comparison from a different year, not a date-specific normal for Oct. 6.
The forecast’s air temperature alone does not establish a heat-index value or a local heat-risk estimate. The National Weather Service notes that direct sunlight can raise the heat index by up to 15°F; that is general guidance, not a calculation for San Antonio on Tuesday.
