San Antonio · May
Run in the pre-dawn.
Average high is 86°F with a 68°F overnight low. Expect 20 rain days — plan around the radar. Humid heat punishes mid-morning — get out before sunrise for the only truly comfortable window.
Avg high / low
86° / 68°F
Humidity
72%
Rain days
20/mo
Wind
13 mph
What May feels like in San Antonio
Sunrise
06:41
Mid-month average
Sunset
20:19
Mid-month average
Time-of-day breakdown
Morning
Coolest, driest air of the day. The window before sunrise is the most reliable comfortable hour.
Midday
Heat peaks here. Skip unless you've got shade and pace tolerance.
Evening
Cools off after sunset but still warm. Good for easy efforts; avoid hard intervals if you're chasing pace.
What to wear running in San Antonio in May
The kit for May in San Antonio: light, breathable, and moisture-wicking — singlet or short-sleeve only, a water-resistant cap or jacket on standby.
May vs the surrounding months
vs April
+5° avg high
+5 rain days
San Antonio in April →
May
86°F avg high
20 rain days
Best: pre-dawn
vs June
-6° avg high
+4 rain days
San Antonio in June →
Frequently Asked Questions
What is the best time of day to run in San Antonio in May?+
Pre-dawn. Humid heat punishes mid-morning — get out before sunrise for the only truly comfortable window.
What's the average temperature in San Antonio in May?+
Average high 86°F, average low 68°F.
How does May compare to surrounding months in San Antonio?+
Compared to April (avg high 81°F), May is warmer. Compared to June (avg high 92°F), May is cooler.
Does it rain often in San Antonio in May?+
Expect about 20 measurable rain days in May, on average.