Merrillville has chilly winters and pleasant summers
A typical July afternoon reaches 83°, a January night drops to 17°, and about 27 inches of snow falls in a normal winter.
A year in Merrillville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Merrillville’s climate
Read from where Merrillville sits among Indiana’s towns. The page puts what stands out first.
About 171 frost-free days a year
In half of years the last 32° night comes by April 29 and the first by October 16.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
27 inches of snow, 39 of rain and melt
June is the wettest month and February the driest. Rain or snow falls on about 112 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
What a year in Merrillville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Living with Merrillville’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
171 frost-free days. The last frost comes by Apr 29 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 16.
About 27" a winter over 8 days with an inch or more, most in January. Snow covers the ground about 29 days a year.
Months averaging under 55° run from October through April. Heating is 89% of the year’s heating-and-cooling load.
About 16 days a year reach 90°, and July afternoons average 83°.
The nicest months are May, June, July, August, September and October. 6.0 miles of trails are waiting.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →Merrillville and its neighbors
Crown Point has the coldest January nights next door (16°) and St. John the hottest July afternoons (84°). Tap a town to see its climate.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Merrillville averaged 1.2° warmer than the 1900s. The biggest change is in December (+2.5°).
A smaller shift than in 53% of U.S. towns.
Change by month
How Merrillville compares
Against every U.S. town on TownTapestry, each counted once, with its place in Indiana.
Merrillville weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 32° | 17° | 2.2" | 10.3" | 10 | 12 | 15° – 37° |
| February | 36° | 20° | 1.9" | 6.3" | 8 | 9 | 16° – 38° |
| March | 47° | 29° | 2.3" | 4.3" | 10 | 3 | 29° – 53° |
| April | 60° | 38° | 3.6" | 0.6" | 10 | 0 | 40° – 55° |
| May | 71° | 49° | 4.3" | 0 | 12 | 0 | 54° – 66° |
| June | 80° | 59° | 4.3" | 0 | 10 | 0 | 65° – 74° |
| July | 83° | 63° | 4.2" | 0 | 9 | 0 | 68° – 78° |
| August | 82° | 61° | 4.2" | 0 | 9 | 0 | 66° – 78° |
| September | 76° | 53° | 3.5" | 0 | 8 | 0 | 59° – 69° |
| October | 64° | 42° | 3.5" | 0 | 10 | 0 | 49° – 59° |
| November | 49° | 32° | 2.7" | 0.4" | 9 | 0 | 33° – 48° |
| December | 37° | 22° | 2.2" | 4.7" | 9 | 5 | 16° – 40° |
| Year | 60° | 40° | 38.9" | 26.6" | 112 | 29 |
Heating and cooling a home in Merrillville
89% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 16° to 40°. June is the most reliable, staying within 9°.
Common questions about Merrillville’s climate
What is the coldest month in Merrillville?
January, with a typical high of 32° and a low of 17°.
What is the hottest month in Merrillville?
July, with a typical high of 83° and a low of 63°. About 16 days a year reach 90°.
How much snow does Merrillville get?
About 27 inches in a normal winter, most of it in January.
When is the first frost in Merrillville?
In half of years the first 32° night comes by October 16, and the last spring frost by April 29.
What is the rainiest month in Merrillville?
June, with 4.3 inches of rain and melted snow. The year totals 39 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in Merrillville.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for Merrillville itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Crown Pt 1n, IN (3 mi, snow) and Lowell, IN (15 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000. Today’s forecast: National Weather Service.