Best time to visit Sullivan, IN

A month-by-month travel weather guide based on NOAA 30-year climate normals.

The most comfortable travel window in Sullivan runs from July through October — 4 months of pleasant temperatures and modest rainfall.

January Cold
High
38.3°F
Low
20.6°F
Precip
3.34 in

Winter weather. Plan around weather; good for snow sports if applicable.

Daylight ≈ 9h 32m

February Cold
High
42.9°F
Low
23.7°F
Precip
2.76 in

Winter weather. Plan around weather; good for snow sports if applicable.

Daylight ≈ 10h 31m

March Cool
High
53.4°F
Low
32.9°F
Precip
3.48 in

Mild but on the chilly side. Pack a jacket; great for hiking and city walks.

Daylight ≈ 11h 44m

April Wet
High
65.8°F
Low
44.1°F
Precip
5.07 in

Frequent rain. Bring waterproof gear; outdoor plans need flexibility.

Daylight ≈ 13h 2m

May Wet
High
74.8°F
Low
54.1°F
Precip
5.23 in

Frequent rain. Bring waterproof gear; outdoor plans need flexibility.

Daylight ≈ 14h 8m

June Wet
High
82.9°F
Low
62.8°F
Precip
5.06 in

Frequent rain. Bring waterproof gear; outdoor plans need flexibility.

Daylight ≈ 14h 42m

July Good
High
85.6°F
Low
66.3°F
Precip
4.67 in

Comfortable for most activities. Bring layers; nights can be cool.

Daylight ≈ 14h 29m

August Good
High
84.8°F
Low
64.7°F
Precip
3.24 in

Comfortable for most activities. Bring layers; nights can be cool.

Daylight ≈ 13h 32m

September Excellent
High
79.4°F
Low
57.1°F
Precip
3.59 in

Sweet spot — comfortable highs in the 65-80°F range, mild nights, low rain. Ideal for nearly any outdoor plan.

Daylight ≈ 12h 14m

October Good
High
67.8°F
Low
45.3°F
Precip
3.79 in

Comfortable for most activities. Bring layers; nights can be cool.

Daylight ≈ 10h 57m

November Cool
High
53.9°F
Low
34.2°F
Precip
3.91 in

Mild but on the chilly side. Pack a jacket; great for hiking and city walks.

Daylight ≈ 9h 49m

December Cold
High
42.7°F
Low
26.1°F
Precip
3.03 in

Winter weather. Plan around weather; good for snow sports if applicable.

Daylight ≈ 9h 16m

Looking for similar climates? See Sullivan's climate twins. Or jump straight to the full climate profile.