Photo: Gage Skidmore · CC BY-SA 3.0The climate in Sullivan sits close to the middle of U.S. towns
The depth of winter brings overnight lows near 22°. Its yearly precipitation tops that of 63% of U.S. towns. The latest 30-year average runs 1.3° warmer than 1901–2000’s, with December up the most. Radiators earn their keep from November to March, the months that average under 50°.
A year in Sullivan at a glance
Each month’s typical high and low, and what it brings.
What stands out about Sullivan’s climate
Compared with towns across the U.S., with Sullivan’s place in Indiana beside it.
What a year in Sullivan feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 193 frost-free days a year
In half of years the last 32° night comes by April 14 and the first by October 26. Frost and day counts come from NOAA’s station at Shakamak Sp, IN, 10 miles from the town’s center, at about the same height.
The 2023 USDA map puts Sullivan’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −5°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 15 inches of snow a winter
Snow, measured at Farmersburg Tv-2, IN, falls mostly in January. Precipitation (rain plus melted snow) adds up to 46 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 121 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Sullivan
81% of the work is heating. Months averaging under 55° run from November through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Shakamak Sp, IN.
Living with Sullivan’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
193 frost-free days in zone 6b. The last frost comes by Apr 14 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 26.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October. 0.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Sullivan from natural hazards, river flooding is the largest share (36%); heat waves, cold waves, winter storms and ice storms together are 13%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Sullivan and similar climates
TownRatings has no climate map of the towns around Sullivan yet.
Climates most like Sullivan’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Sullivan, IN | 22° | 87° | 46" | 15" |
| Loveland, OH | 23° | 86° | 44" | 14" |
| Collegeville, PA | 23° | 88° | 47" | 13" |
| Bel Air North, MD | 24° | 87° | 47" | 18" |
| Wright City, MO | 21° | 88° | 43" | 14" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Sullivan averaged 1.3° warmer than the 1900s. The biggest change is in December (+2.3°).
A smaller shift than in 56% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Sullivan compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Sullivan’s place among Indiana’s.
Sullivan weather by month
Highs, lows and precipitation from NOAA’s grid at Sullivan’s center; snow, wet days and snow on the ground from Farmersburg Tv-2, IN. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 38° | 22° | 3.0" | 5.3" | 11 | 10 | 22° – 41° |
| February | 43° | 25° | 2.5" | 3.6" | 10 | 6 | 21° – 43° |
| March | 54° | 33° | 3.6" | 1.7" | 11 | 1 | 36° – 57° |
| April | 66° | 43° | 4.9" | 0.0" | 12 | 0 | 48° – 60° |
| May | 75° | 54° | 5.1" | 0.0" | 13 | 0 | 59° – 74° |
| June | 84° | 62° | 5.1" | 0.0" | 11 | 0 | 68° – 77° |
| July | 87° | 66° | 4.4" | 0.0" | 10 | 0 | 71° – 83° |
| August | 85° | 64° | 3.1" | 0.0" | 8 | 0 | 70° – 80° |
| September | 80° | 56° | 3.4" | 0.0" | 8 | 0 | 64° – 73° |
| October | 68° | 45° | 3.8" | 0.1" | 9 | 0 | 52° – 61° |
| November | 54° | 34° | 3.7" | 0.5" | 10 | 1 | 36° – 51° |
| December | 42° | 26° | 3.1" | 3.9" | 11 | 6 | 21° – 43° |
| Year | 64° | 44° | 45.6" | 15.1" | 121 | 23 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 21° to 43°. June is the most reliable, staying within 8°.
Where Sullivan’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Sullivan’s center.
- Snow: Farmersburg Tv-2, IN.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Shakamak Sp, IN, 10 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Sullivan’s climate
What is the weather like in Sullivan?
A typical July afternoon reaches 87°, a January night drops to 22°, and about 15 inches of snow falls in a normal winter. Colder January nights than 52% of U.S. towns; hotter July afternoons than 60% of U.S. towns.
How cold does it get in Sullivan in winter?
January nights average 22°. About 113 nights a year reach 32° or below and 5 reach 0° or below. In the coldest January of the last 30 years the month averaged 22°.
How much snow does Sullivan get?
About 15 inches in a normal winter at Farmersburg Tv-2, IN, most of it in January, with snow on the ground about 23 days a year.
How hot does it get in Sullivan?
July, with a typical high of 87° and a low of 66°. About 19 days a year reach 90° (Shakamak Sp, IN).
When is the first and last frost in Sullivan?
In half of years the last spring frost (32°) comes by April 14 and the first fall frost by October 26, about 193 frost-free days, at Shakamak Sp, IN.
What growing zone is Sullivan in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −5°.
What is the best time of year to visit Sullivan?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Sullivan getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 56% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Sullivan.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.