In the thick of a warm summer and fall, it can be hard to imagine that it *ever* cools below 90 degrees regularly in San Antonio.
But fear not! We’ll eventually enjoy true sweater weather. It just takes a little patience.
So, when does it, on average, cool below 90 degrees in the Alamo City?
KEY POINTS:
- Average last 90-degree day happens in mid-October for San Antonio
- Actual date varies year-to-year
- Latest to ever hit 90°? Christmas Day 1955
AVERAGE LAST 90° DAY
As meteorologists, we look at the last 30 years for average temperature or precipitation data.
Why 30 years? This amount of time is long enough to account for natural variability from long-term patterns that impact our weather, like La Niña or El Niño.
So, when looking at 1994 to 2024, the average last day with a high at or above 90 degrees in San Antonio works out to Oct. 19.
RECENT HISTORY
Oct. 19 is just the average last day we see a high of 90° or greater. We know that it varies year-to-year. Take a look at just the last 5 years:
Just last year, we had to wait until Nov. 4 to say goodbye to the 90s!
EXTREMES
Let’s take a look back beyond the past 30 years. Temperature records for San Antonio date back to 1885! In that time, we’ve seen:
- EARLIEST END TO 90s: Sept. 2, 1974
- LATEST 90° DAY: Christmas Day, 1955
WHAT WILL HAPPEN THIS YEAR?
October 2025 begins warm for San Antonio. We’ll likely not see an end to the 90s until beyond mid-October. We’ll keep you posted!
- Read more from the meteorologists on the Whatever the Weather page
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