William Gonnerman House · Photo: Nyttend · Public domainIn Mount Vernon, July heat, January chill and rainfall all sit near the middle of U.S. towns
The warmest part of a July day comes in at 88° on average. Seasons differ by 63°, from the coldest nights to the warmest afternoons. It is a wet place: more rain and snow fall here than on 69% of U.S. towns. Plan time outside for April, May, September and October, when highs sit at 68–81°.
A year in Mount Vernon at a glance
Each month’s typical high and low, and what it brings.
What stands out about Mount Vernon’s climate
Compared with towns across the U.S., with Mount Vernon’s place in Indiana beside it.
What a year in Mount Vernon feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 202 frost-free days a year
In half of years the last 32° night comes by April 7 and the first by October 28. Frost and day counts come from NOAA’s station at Mt Vernon, IN, 0.6 miles from the town’s center, at about the same height.
The 2023 USDA map puts Mount Vernon’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 3°. 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 8 inches of snow a winter
Snow, measured at Mt Vernon, IN, falls mostly in February. Precipitation (rain plus melted snow) adds up to 47 inches a year; April 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 Mount Vernon
77% 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 Mt Vernon, IN.
Living with Mount Vernon’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
202 frost-free days in zone 7a. The last frost comes by Apr 7 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 28.
Months with highs of 62–84° and lows of 40° or more: April, May, September and October. 0.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Mount Vernon from natural hazards, river flooding is the largest share (48%); heat waves, cold waves, winter storms and ice storms together are 6%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Mount Vernon and its neighbors
Every town next door is within a degree of Mount Vernon in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Mount Vernon’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 |
|---|---|---|---|---|
| Mount Vernon, IN | 25° | 88° | 47" | 8.4" |
| Collinsville, VA | 27° | 88° | 46" | 9.4" |
| Harrison, AR | 26° | 89° | 47" | 9.5" |
| Penn Wynne, PA | 25° | 87° | 47" | 7.6" |
| Monett, MO | 24° | 89° | 47" | 6.7" |
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 Mount Vernon averaged 0.6° warmer than the 1900s. The biggest change is in February (+1.6°).
A smaller shift than in 96% 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 Mount Vernon compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Mount Vernon’s place among Indiana’s.
Mount Vernon weather by month
Highs, lows and precipitation from NOAA’s grid at Mount Vernon’s center; snow, wet days and snow on the ground from Mt Vernon, IN. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 42° | 25° | 3.3" | 2.4" | 9 | 27° – 43° |
| February | 46° | 28° | 3.1" | 3.1" | 8 | 26° – 45° |
| March | 57° | 37° | 4.4" | 1.5" | 10 | 40° – 59° |
| April | 68° | 46° | 5.0" | 0.0" | 11 | 50° – 62° |
| May | 77° | 57° | 4.9" | 0.0" | 11 | 61° – 73° |
| June | 85° | 65° | 4.3" | 0.0" | 9 | 70° – 80° |
| July | 88° | 69° | 4.4" | 0.0" | 8 | 73° – 84° |
| August | 87° | 67° | 3.3" | 0.0" | 6 | 72° – 83° |
| September | 81° | 59° | 3.3" | 0.0" | 7 | 66° – 75° |
| October | 70° | 47° | 3.3" | 0.2" | 7 | 55° – 64° |
| November | 56° | 37° | 3.9" | 0.1" | 9 | 39° – 53° |
| December | 45° | 29° | 3.8" | 1.1" | 10 | 24° – 46° |
| Year | 67° | 47° | 46.8" | 8.4" | 104 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 24° to 46°. September is the most reliable, staying within 9°.
Where Mount Vernon’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 Mount Vernon’s center.
- Snow: Mt Vernon, IN (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Mt Vernon, IN, 0.6 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 Mount Vernon’s climate
What is the weather like in Mount Vernon?
A typical July afternoon reaches 88°, a January night drops to 25°, and about 8 inches of snow falls in a normal winter. Milder January nights than 64% of U.S. towns; hotter July afternoons than 67% of U.S. towns.
How cold does it get in Mount Vernon in winter?
January nights average 25°. About 86 nights a year reach 32° or below and 1 reach 0° or below. In the coldest January of the last 30 years the month averaged 27°.
How much snow does Mount Vernon get?
About 8.4 inches in a normal winter at Mt Vernon, IN, most of it in February.
How hot does it get in Mount Vernon?
July, with a typical high of 88° and a low of 69°. About 34 days a year reach 90° (Mt Vernon, IN).
When is the first and last frost in Mount Vernon?
In half of years the last spring frost (32°) comes by April 7 and the first fall frost by October 28, about 202 frost-free days, at Mt Vernon, IN.
What growing zone is Mount Vernon in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 3°.
What is the best time of year to visit Mount Vernon?
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 Mount Vernon getting warmer?
Yes: 1991–2020 averaged 0.6° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 96% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Mount Vernon.
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.