Early autumn · Weather & things to do
Indiana Dunes in September
Indiana Dunes cools off: highs slip to 76°F (24°C), from 82°F in August, with lows of 57°F (14°C) and about 3.1 in (80 mm) of rain.
September opens the best stretch on our comfort score, at 88/100 (the top score of the year).
- Avg high
- 76°F (24°C)
- Avg low
- 57°F (14°C)
- Rain
- 3.1 in (80 mm)
- Humidity
- 73%
- Cloud cover
- 46%
- Daylight
- ~12 h 16 min
- Comfort score
- 88/100 · Great
What September feels like
Warm afternoons near 76°F (24°C) make long days outdoors easy.
After dark, temperatures fall to about 57°F (14°C).
Some rain is likely, about 3.1 in (80 mm) in the month, so pack for a shower or two.
Plan around September
September is one of Indiana Dunes's best months on the climate data.
- Last warm month for a while: October highs fall to 62°F.
- Opens the best-scoring stretch on our comfort score: September.
- Comfort improves from 81/100 in August to 88/100.
- September sits inside the May – Oct window our Indiana & Ohio City-Nature Loop recommends.
What to pack for September
- Light, breathable clotheshighs average 76°F
- Packable rain jacket or umbrellaa shower or two is likely
- Comfortable walking shoesmost places below are best reached on foot or with short walks
What to do in Indiana Dunes in September
With conditions on your side, the picks below favor time outside.
Chellberg Farm and Bailly Homestead
Restored 1880s Swedish farmstead and fur-trader homestead linked by trails.
Lucrezia Café
Northern Italian restaurant in a historic Chesterton house.
Great Marsh Trail
Flat loop through restored wetlands, good for birding.
Why now September scores 88/100 for comfort, good conditions for being outside.
3 Dune Challenge
1.5-mile climb over the state park's three tallest dunes, 552 vertical feet in sand.
Why now Highs near 76°F and 3.1 in of monthly rain make this an easy outdoor pick.
Indiana Dunes Visitor Center
Joint national and state park visitor center for maps, passes and trail conditions.
Why now One to do outside while the weather is on your side.
Nearby in September
- Chicago in September~34 mi · highs 71°F, 3.4 in rain · 3°C (5°F) cooler by day, about as wet
- Holland in September~92 mi · highs 70°F, 3.2 in rain · 3°C (6°F) cooler by day, about as wet
- Milwaukee in September~105 mi · highs 74°F, 3.5 in rain · 1°C (2°F) cooler by day, about as wet
- Broad Ripple in September~132 mi · highs 78°F, 3.2 in rain · 1°C (2°F) warmer by day, about as wet
NASA POWER 2001–2025 monthly averages on a ~50 km grid. Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
Indiana Dunes in September: quick answers
Is September a good time to visit Indiana Dunes?
Yes. On the climate data it's one of the best months, scoring 88/100. Expect highs of 76°F (24°C) and 3.1 in (80 mm) of rain. September is inside the May – Oct window our Indiana & Ohio City-Nature Loop recommends.
How hot is Indiana Dunes in September?
Average highs are 76°F (24°C) and average lows 57°F (14°C), making it the 4th-warmest month by daytime highs.
Does it rain a lot in Indiana Dunes in September?
Some: about 3.1 in (80 mm) of rain falls across September on average, the 6th-driest month of the year. The annual total is about 38.7 in (984 mm).
What should I pack for Indiana Dunes in September?
Bring light, breathable clothes (highs average 76°F), packable rain jacket or umbrella (a shower or two is likely) and comfortable walking shoes (most places below are best reached on foot or with short walks).
More on Indiana Dunes
Routes in season in September
- Indiana & Ohio City-Nature Loop May – Oct
Planning Indiana Dunes in September?
Bring the crew into one shared trip: vote on dates, build the day-by-day plan, split costs and share one packing list.