Morris, Illinois climate: Normal weather by month, frost dates and records
Morris's normal year runs from 16°F January nights to 85°F July afternoons, with 38.8 inches of precipitation and 25 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.4°C, January lows of −9°C, July highs of 29°C, 985 mm of precipitation a year.
- NOAA stationMorris (1 mi NW)
- Station IDUSC00115825
- Location41.37°N 88.43°W
- Elevation524 ft (160 m)
- From the centerunder 1 mile
- Population14,587
On October 23, the normal high in Morris is 61°F and the normal low 40°F, and the chance of measurable rain or snow is 32%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Morris.
- Jan 31° 16°
- Feb 36° 19°
- Mar 48° 29°
- Apr 61° 40°
- May 72° 51°
- Jun 82° 61°
- Jul 85° 65°
- Aug 83° 63°
- Sep 77° 55°
- Oct 64° 43°
- Nov 49° 32°
- Dec 37° 22°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Morris each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 16°F. The most precipitation falls in July (4.92 in), the least in February (1.79 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 16°F | 23.4°F | 2.09 | 7.4 | 10 | <1 | 28 | 9 h 30 min |
| February | 36°F | 19°F | 27.4°F | 1.79 | 7.5 | 8 | <1 | 25 | 10 h 40 min |
| March | 48°F | 29°F | 38.3°F | 2.23 | 2.9 | 9 | <1 | 21 | 11 h 50 min |
| April | 61°F | 40°F | 50.3°F | 3.34 | 0.5 | 11 | <1 | 6 | 13 h 20 min |
| May | 72°F | 51°F | 61.6°F | 4.39 | 0.0 | 13 | 1 | <1 | 14 h 30 min |
| June | 82°F | 61°F | 71.4°F | 4.72 | 0.0 | 11 | 5 | <1 | 15 h 10 min |
| July | 85°F | 65°F | 75.0°F | 4.92 | 0.0 | 9 | 7 | <1 | 14 h 50 min |
| August | 83°F | 63°F | 72.8°F | 4.01 | 0.0 | 10 | 4 | <1 | 13 h 50 min |
| September | 77°F | 55°F | 66.1°F | 3.55 | 0.0 | 8 | 3 | <1 | 12 h 30 min |
| October | 64°F | 43°F | 53.6°F | 3.23 | 0.0 | 10 | <1 | 4 | 11 h 10 min |
| November | 49°F | 32°F | 40.3°F | 2.50 | 1.1 | 8 | <1 | 16 | 9 h 50 min |
| December | 37°F | 22°F | 29.1°F | 2.02 | 5.3 | 9 | <1 | 26 | 9 h 10 min |
| Year (annual) | 60°F | 41°F | 50.8°F | 38.79 | 24.7 | 117 | 20 | 127 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −9°C | −4.8°C | 53 mm | 19 cm |
| February | 2°C | −7°C | −2.6°C | 45 mm | 19 cm |
| March | 9°C | −2°C | 3.5°C | 57 mm | 7 cm |
| April | 16°C | 4°C | 10.2°C | 85 mm | 1 cm |
| May | 22°C | 11°C | 16.4°C | 112 mm | 0 cm |
| June | 28°C | 16°C | 21.9°C | 120 mm | 0 cm |
| July | 29°C | 18°C | 23.9°C | 125 mm | 0 cm |
| August | 28°C | 17°C | 22.7°C | 102 mm | 0 cm |
| September | 25°C | 13°C | 18.9°C | 90 mm | 0 cm |
| October | 18°C | 6°C | 12.0°C | 82 mm | 0 cm |
| November | 9°C | 0°C | 4.6°C | 64 mm | 3 cm |
| December | 3°C | −6°C | −1.6°C | 51 mm | 13 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115825; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Morris?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (8).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115825.
When is the last frost in Morris?
In Morris, the last spring frost (32°F) comes after April 20 in half of years and after May 6 in one year in ten; the first autumn frost comes before October 23 in half of years and before October 9 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 201 year in 10 after May 6; 9 in 10 after April 6
- First autumn frost, half of years before
- October 231 year in 10 before October 9; 9 in 10 before November 3
NOAA puts the median frost-free season at 184 days, and the season without a hard freeze (28°F) at 208 days.
A hard freeze (28°F) comes after April 8 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Morris in zone 5b in ZIP code 60450, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Morris's NOAA station is in zone 5b: the coldest night of a typical year reaches −10°F (24 complete years).
Frost dates for every NOAA station in Illinois · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00115825; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Morris?
In a normal year in Morris, 20 days a year reach 90°F, 127 nights fall to 32°F or colder and 117 days bring measurable precipitation.
- Days at 90°F or more
- 20a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 127a normal year
- Days that stay below freezing
- 43high of 32°F or less
- Days with 0.01 inch of precipitation
- 117a normal year
- Days with 1 inch of snow or more
- 9a normal year
The highest temperature in this station's record (since 1912) is 109°F, on July 14, 1936; the lowest is −26°F, on December 28, 1924.
The wettest calendar year on that record is 2019, with 59.06 in; the snowiest season is 1929–30, with 59.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00115825; records: ACIS (NOAA Regional Climate Centers), station USC00115825. Records use complete months only; a month missing more than three days is left out.
How sunny is Morris?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Morris, 3.9 kWh per square metre a day. July is the sunniest month (81%) and January the cloudiest (61%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 61% | 1.7 |
| February | 65% | 2.6 |
| March | 67% | 3.6 |
| April | 70% | 4.8 |
| May | 71% | 5.5 |
| June | 77% | 6.1 |
| July | 81% | 6.2 |
| August | 80% | 5.4 |
| September | 80% | 4.5 |
| October | 71% | 3.0 |
| November | 67% | 2.0 |
| December | 61% | 1.5 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Morris need?
A normal year in Morris brings 6,141 heating degree days, 14% more than the median U.S. place (5,373), and 995 cooling degree days, 10% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,357 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,288 | 0 |
| February | 1,051 | 0 |
| March | 830 | 2 |
| April | 451 | 8 |
| May | 181 | 74 |
| June | 25 | 218 |
| July | 3 | 312 |
| August | 6 | 249 |
| September | 82 | 114 |
| October | 371 | 17 |
| November | 741 | 0 |
| December | 1,113 | 0 |
| Year (annual) | 6,141 | 995 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115825. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Morris been warmer than normal lately?
2025 averaged 52.2°F, 1.4°F above the 1991-2020 normal of 50.8°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 52.3°F | +1.5°F | 36.55 | 26.9 |
| 2022 | 50.4°F | −0.4°F | 31.82 | 26.3 |
| 2023 | 53.5°F | +2.7°F | 34.48 | 8.3 |
| 2024 | 55.1°F | +4.3°F | 41.10 | 14.5 |
| 2025 | 52.2°F | +1.4°F | 31.97 | 20.7 |
Over 71 complete years from 1913 to 2025, the station's annual mean temperature rose at a fitted 1.4°F per century (+0.07°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00115825; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Morris's climate compare?
Morris is warmer than 49 of the other 143 places with their own NOAA record in Illinois, and wetter than 48. Across the 7,247 U.S. stations with normals, its annual mean of 50.8°F is warmer than 44%.
In the Köppen classification computed from these normals, Morris is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Morris share this climate record?
4 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Mazon, IL982 people · 9 mi S
- Newark, IL980 people · 14 mi NW
- Millington, IL624 people · 16 mi NW
- Lisbon, IL274 people · 8 mi N
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Morris's climate
What is the coldest month in Morris?
January, with a normal high of 31°F and a normal low of 16°F. The warmest is July (85°F by day, 65°F at night).
Does it snow in Morris?
Yes: 25 inches in a normal year, falling on 18 days with 0.1 inch or more, the most in February (7.5 inches).
What is the rainiest month in Morris?
July, with 4.92 in of precipitation in a normal year; the driest is February with 1.79 in.
What plant hardiness zone is Morris in?
The USDA's 2023 map puts Morris in zone 5b in ZIP code 60450, the nearest ZIP area. By the same method at Morris's NOAA station, the coldest night of a typical year reaches −10°F (24 years, 1991-2020): zone 5b.
How late can frost come in Morris?
In half of years the last 32°F night comes after April 20; in one year in ten it comes after May 6. Waiting until May 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Channahon, IL8 miles from this station, 51.1°F a year
- Marseilles, IL17 miles from this station, 49.7°F a year
- Dwight, IL18 miles from this station, 49.3°F a year
- Joliet, IL19 miles from this station, 50.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made