Jacksonville · August
Run in the pre-dawn.
Average high is 88°F with a 76°F overnight low. Humidity averages 83% — the limiting factor on most runs. Expect 27 rain days — plan around the radar. Humid heat punishes mid-morning — get out before sunrise for the only truly comfortable window.
Avg high / low
88° / 76°F
Humidity
83%
Rain days
27/mo
Wind
10 mph
What August feels like in Jacksonville
Sunrise
06:54
Mid-month average
Sunset
20:06
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 Jacksonville in August
The kit for August in Jacksonville: light, breathable, and moisture-wicking — singlet or short-sleeve only, a water-resistant cap or jacket on standby.
August vs the surrounding months
vs July
-1° avg high
+1 rain days
Jacksonville in July →
August
88°F avg high
27 rain days
Best: pre-dawn
vs September
+3° avg high
+6 rain days
Jacksonville in September →
Frequently Asked Questions
What is the best time of day to run in Jacksonville in August?+
Pre-dawn. Humid heat punishes mid-morning — get out before sunrise for the only truly comfortable window.
What's the average temperature in Jacksonville in August?+
Average high 88°F, average low 76°F.
How does August compare to surrounding months in Jacksonville?+
Compared to July (avg high 89°F), August is cooler. Compared to September (avg high 85°F), August is warmer.
Does it rain often in Jacksonville in August?+
Expect about 27 measurable rain days in August, on average.