Photo: Ben Jacobson (Kranar Drogin) · CC BY 2.5Mount Morris’ winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 83°, a January night drops to 13°, and about 32 inches of snow falls in a normal winter.
A year in Mount Morris at a glance
Each month’s typical high and low, and what it brings.
What stands out about Mount Morris’ climate
Compared with towns across the U.S., with Mount Morris’ place in Illinois beside it.
What a year in Mount Morris feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 161 frost-free days a year
In half of years the last 32° night comes by April 29 and the first by October 7. Frost and day counts come from NOAA’s station at Polo 5nw, IL, 9 miles from the town’s center, at about the same height.
The 2023 USDA map puts Mount Morris’ center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −15°. 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 32 inches of snow a winter
Snow, measured at Oregon, IL, falls mostly in January. Precipitation (rain plus melted snow) adds up to 39 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 88 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Mount Morris
89% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October 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 Polo 5nw, IL.
Living with Mount Morris’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
161 frost-free days in zone 5b. 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 7.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August, September and October. 0.8 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Mount Morris from natural hazards, river flooding is the largest share (52%); heat waves, cold waves, winter storms and ice storms together are 17%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Mount Morris and similar climates
TownRatings has no climate map of the towns around Mount Morris yet.
Climates most like Mount Morris’, 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 Morris, IL | 13° | 83° | 39" | 32" |
| Grinnell, IA | 12° | 84° | 38" | 31" |
| Kendallville, IN | 17° | 83° | 38" | 36" |
| Ghent, NY | 16° | 84° | 42" | 31" |
| Sayre, PA | 17° | 84° | 37" | 35" |
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 Mount Morris averaged 1.3° warmer than the 1900s. The biggest change is in December (+2.7°).
A smaller shift than in 53% 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 Morris compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Mount Morris’ place among Illinois’.
Mount Morris weather by month
Highs, lows and precipitation from NOAA’s grid at Mount Morris’ center; snow, wet days and snow on the ground from Oregon, IL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 29° | 13° | 1.7" | 13.6" | 7 | 11° – 33° |
| February | 34° | 17° | 1.8" | 6.7" | 6 | 12° – 37° |
| March | 46° | 27° | 2.5" | 3.0" | 7 | 29° – 52° |
| April | 60° | 37° | 3.8" | 0.8" | 8 | 40° – 55° |
| May | 71° | 49° | 4.6" | 0.0" | 10 | 54° – 66° |
| June | 80° | 59° | 5.3" | 0.0" | 9 | 66° – 74° |
| July | 83° | 62° | 4.2" | 0.0" | 7 | 67° – 79° |
| August | 81° | 60° | 4.1" | 0.0" | 7 | 65° – 77° |
| September | 75° | 52° | 3.6" | 0.0" | 7 | 58° – 69° |
| October | 62° | 41° | 3.0" | 0.0" | 7 | 47° – 58° |
| November | 47° | 30° | 2.5" | 1.5" | 6 | 30° – 47° |
| December | 34° | 19° | 2.0" | 6.7" | 7 | 12° – 37° |
| Year | 58° | 39° | 39.0" | 32.3" | 88 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 12° to 37°. June is the most reliable, staying within 8°.
Where Mount Morris’ 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 Morris’ center.
- Snow: Oregon, IL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Polo 5nw, IL, 9 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 Morris’ climate
What is the weather like in Mount Morris?
A typical July afternoon reaches 83°, a January night drops to 13°, and about 32 inches of snow falls in a normal winter. Colder January nights than 90% of U.S. towns; cooler July afternoons than 69% of U.S. towns.
How cold does it get in Mount Morris in winter?
January nights average 13°. About 138 nights a year reach 32° or below and 13 reach 0° or below. In the coldest January of the last 30 years the month averaged 11°.
How much snow does Mount Morris get?
About 32 inches in a normal winter at Oregon, IL, most of it in January.
How hot does it get in Mount Morris?
July, with a typical high of 83° and a low of 62°. About 17 days a year reach 90° (Polo 5nw, IL).
When is the first and last frost in Mount Morris?
In half of years the last spring frost (32°) comes by April 29 and the first fall frost by October 7, about 161 frost-free days, at Polo 5nw, IL.
What growing zone is Mount Morris in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −15°.
What is the best time of year to visit Mount Morris?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Mount Morris getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 53% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Mount Morris.
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.