Photo: Brian Stansberry · CC BY 4.0More precipitation falls on Somerville than on 81% of U.S. towns: 49 inches a year
Nights in January average 23°. Expect the heaviest rain or snow in May and the lightest in February. In July, afternoons here are warmer than in 65% of U.S. towns. Comfortable outdoor weather, highs of 68–81°, belongs to April, May, September and October.
A year in Somerville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Somerville’s climate
Compared with towns across the U.S., with Somerville’s place in Indiana beside it.
What a year in Somerville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 194 frost-free days a year
In half of years the last 32° night comes by April 13 and the first by October 25. Frost and day counts come from NOAA’s station at Princeton 1 W, IN, 13 miles from the town’s center, at about the same height.
The 2023 USDA map puts Somerville’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 0°. 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 12 inches of snow a winter
Snow, measured at Princeton 1 W, IN, falls mostly in January, February and December. Precipitation (rain plus melted snow) adds up to 49 inches a year; May is the wettest month and February the driest. Rain or snow falls on about 104 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Somerville
79% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Princeton 1 W, IN.
Living with Somerville’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
194 frost-free days in zone 7a. The last frost comes by Apr 13 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 25.
Months with highs of 62–84° and lows of 40° or more: April, May, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Somerville from natural hazards, earthquakes are the largest share (29%); heat waves, cold waves, winter storms and ice storms together are 9%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Somerville and similar climates
TownRatings has no climate map of the towns around Somerville yet.
Climates most like Somerville’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 |
|---|---|---|---|---|
| Somerville, IN | 23° | 88° | 49" | 12" |
| Collegeville, PA | 23° | 88° | 47" | 13" |
| Paris, KY | 24° | 87° | 49" | 15" |
| Hockessin, DE | 24° | 86° | 48" | 12" |
| Aurora, MO | 24° | 89° | 47" | 12" |
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 Somerville averaged 1.1° warmer than the 1900s. The biggest change is in December (+1.9°).
A smaller shift than in 73% 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 Somerville compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Somerville’s place among Indiana’s.
Somerville weather by month
Highs, lows and precipitation from NOAA’s grid at Somerville’s center; snow, wet days and snow on the ground from Princeton 1 W, IN. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 40° | 23° | 3.4" | 3.6" | 9 | 25° – 42° |
| February | 45° | 26° | 3.1" | 3.4" | 8 | 24° – 45° |
| March | 56° | 35° | 4.4" | 1.2" | 10 | 38° – 59° |
| April | 68° | 44° | 5.2" | 0.0" | 10 | 50° – 61° |
| May | 77° | 55° | 5.4" | 0.0" | 11 | 60° – 73° |
| June | 85° | 64° | 4.8" | 0.0" | 9 | 69° – 79° |
| July | 88° | 67° | 4.4" | 0.0" | 9 | 72° – 83° |
| August | 87° | 65° | 3.1" | 0.0" | 7 | 71° – 82° |
| September | 81° | 57° | 3.8" | 0.0" | 7 | 64° – 75° |
| October | 69° | 45° | 3.5" | 0.1" | 7 | 53° – 63° |
| November | 55° | 35° | 4.1" | 0.2" | 8 | 38° – 51° |
| December | 44° | 28° | 3.9" | 3.7" | 9 | 23° – 45° |
| Year | 66° | 45° | 49.1" | 12.2" | 104 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 23° to 45°. June is the most reliable, staying within 9°.
Where Somerville’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 Somerville’s center.
- Snow: Princeton 1 W, IN.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Princeton 1 W, IN, 13 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 Somerville’s climate
What is the weather like in Somerville?
A typical July afternoon reaches 88°, a January night drops to 23°, and about 12 inches of snow falls in a normal winter. Milder January nights than 58% of U.S. towns; hotter July afternoons than 65% of U.S. towns.
How cold does it get in Somerville in winter?
January nights average 23°. About 100 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 25°.
How much snow does Somerville get?
About 12 inches in a normal winter at Princeton 1 W, IN, most of it in January, February and December.
How hot does it get in Somerville?
July, with a typical high of 88° and a low of 67°. About 38 days a year reach 90° (Princeton 1 W, IN).
When is the first and last frost in Somerville?
In half of years the last spring frost (32°) comes by April 13 and the first fall frost by October 25, about 194 frost-free days, at Princeton 1 W, IN.
What growing zone is Somerville in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 0°.
What is the best time of year to visit Somerville?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Somerville getting warmer?
Yes: 1991–2020 averaged 1.1° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 73% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Somerville.
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.