Morrison, Illinois climate: Normal weather by month, frost dates and records
Morrison's normal year runs from 12°F January nights to 83°F July afternoons, with 38.3 inches of precipitation and 32 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.1°C, January lows of −11°C, July highs of 28°C, 972 mm of precipitation a year.
- NOAA stationMorrison
- Station IDUSC00115833
- Location41.79°N 89.97°W
- Elevation632 ft (193 m)
- From the center1 miles
- Population3,988
On October 23, the normal high in Morrison is 59°F and the normal low 37°F, and the chance of measurable rain or snow is 24%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Morrison.
- Jan 29° 12°
- Feb 34° 16°
- Mar 46° 27°
- Apr 60° 37°
- May 71° 49°
- Jun 80° 59°
- Jul 83° 62°
- Aug 81° 60°
- Sep 75° 51°
- Oct 62° 39°
- Nov 47° 28°
- Dec 35° 18°
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 Morrison each month?
July is the warmest month, with normal highs of 83°F; January the coldest, with normal lows of 12°F. The most precipitation falls in June (4.93 in), the least in January (1.51 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 29°F | 12°F | 20.4°F | 1.51 | 10.4 | 8 | <1 | 30 | 9 h 30 min |
| February | 34°F | 16°F | 24.6°F | 1.65 | 7.6 | 6 | <1 | 26 | 10 h 30 min |
| March | 46°F | 27°F | 36.4°F | 2.53 | 3.6 | 7 | <1 | 23 | 11 h 50 min |
| April | 60°F | 37°F | 48.2°F | 3.84 | 0.8 | 10 | <1 | 9 | 13 h 20 min |
| May | 71°F | 49°F | 59.8°F | 4.73 | 0.0 | 11 | 1 | 1 | 14 h 30 min |
| June | 80°F | 59°F | 69.2°F | 4.93 | 0.0 | 10 | 5 | <1 | 15 h 10 min |
| July | 83°F | 62°F | 72.5°F | 4.16 | 0.0 | 7 | 6 | <1 | 15 h |
| August | 81°F | 60°F | 70.4°F | 4.32 | 0.0 | 8 | 4 | <1 | 13 h 50 min |
| September | 75°F | 51°F | 63.1°F | 3.35 | 0.0 | 7 | 2 | 1 | 12 h 30 min |
| October | 62°F | 39°F | 50.8°F | 2.77 | 0.1 | 7 | <1 | 8 | 11 h 10 min |
| November | 47°F | 28°F | 37.8°F | 2.47 | 2.7 | 7 | <1 | 20 | 9 h 50 min |
| December | 35°F | 18°F | 26.4°F | 2.02 | 6.3 | 8 | <1 | 29 | 9 h 10 min |
| Year (annual) | 59°F | 38°F | 48.3°F | 38.28 | 31.5 | 96 | 17 | 145 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −11°C | −6.4°C | 38 mm | 26 cm |
| February | 1°C | −9°C | −4.1°C | 42 mm | 19 cm |
| March | 8°C | −3°C | 2.4°C | 64 mm | 9 cm |
| April | 15°C | 3°C | 9.0°C | 98 mm | 2 cm |
| May | 22°C | 9°C | 15.4°C | 120 mm | 0 cm |
| June | 27°C | 15°C | 20.7°C | 125 mm | 0 cm |
| July | 28°C | 17°C | 22.5°C | 106 mm | 0 cm |
| August | 27°C | 15°C | 21.3°C | 110 mm | 0 cm |
| September | 24°C | 11°C | 17.3°C | 85 mm | 0 cm |
| October | 17°C | 4°C | 10.4°C | 70 mm | 0 cm |
| November | 8°C | −2°C | 3.2°C | 63 mm | 7 cm |
| December | 1°C | −8°C | −3.1°C | 51 mm | 16 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115833; 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 Morrison?
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 (7).
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 USC00115833.
When is the last frost in Morrison?
In Morrison, the last spring frost (32°F) comes after April 26 in half of years and after May 11 in one year in ten; the first autumn frost comes before October 13 in half of years and before September 30 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 261 year in 10 after May 11; 9 in 10 after April 13
- First autumn frost, half of years before
- October 131 year in 10 before September 30; 9 in 10 before October 25
NOAA puts the median frost-free season at 167 days, and the season without a hard freeze (28°F) at 189 days.
A hard freeze (28°F) comes after April 15 in half of springs and before October 23 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Morrison in zone 5b in ZIP code 61270, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Morrison's NOAA station is in zone 5a: the coldest night of a typical year reaches −15°F (29 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Illinois · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00115833; 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 Morrison?
In a normal year in Morrison, 17 days a year reach 90°F, 145 nights fall to 32°F or colder and 96 days bring measurable precipitation.
- Days at 90°F or more
- 17a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 145a normal year
- Days that stay below freezing
- 44high of 32°F or less
- Days with 0.01 inch of precipitation
- 96a normal year
- Days with 1 inch of snow or more
- 12a normal year
The highest temperature in this station's record (since 1895) is 112°F, on July 14, 1936; the lowest is −35°F, on January 31, 2019.
The wettest calendar year on that record is 1973, with 51.38 in; the snowiest season is 1935–36, with 59.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00115833; records: ACIS (NOAA Regional Climate Centers), station USC00115833. Records use complete months only; a month missing more than three days is left out.
How sunny is Morrison?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Morrison, 4.0 kWh per square metre a day. July is the sunniest month (81%) and December the cloudiest (63%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 1.8 |
| February | 68% | 2.7 |
| March | 68% | 3.7 |
| April | 70% | 4.8 |
| May | 72% | 5.5 |
| June | 77% | 6.2 |
| July | 81% | 6.3 |
| August | 80% | 5.5 |
| September | 80% | 4.5 |
| October | 72% | 3.0 |
| November | 68% | 2.0 |
| December | 63% | 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 Morrison need?
A normal year in Morrison brings 6,747 heating degree days, 26% more than the median U.S. place (5,373), and 705 cooling degree days, 22% fewer 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 2,876 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,381 | 0 |
| February | 1,130 | 0 |
| March | 885 | 0 |
| April | 507 | 3 |
| May | 206 | 45 |
| June | 32 | 160 |
| July | 6 | 240 |
| August | 14 | 181 |
| September | 125 | 68 |
| October | 447 | 7 |
| November | 816 | 0 |
| December | 1,197 | 0 |
| Year (annual) | 6,747 | 705 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115833. 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 Morrison been warmer than normal lately?
2025 averaged 49.6°F, 1.3°F above the 1991-2020 normal of 48.3°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.5°F | +1.3°F | 27.32 | 25.3 |
| 2022 | 47.7°F | −0.6°F | 35.97 | 16.9 |
| 2023 | 50.6°F | +2.3°F | – | – |
| 2024 | 51.8°F | +3.5°F | 32.45 | 27.0 |
| 2025 | 49.6°F | +1.3°F | 29.98 | 18.1 |
Over 92 complete years from 1902 to 2025, the station's annual mean temperature rose at a fitted 2.0°F per century (+0.11°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00115833; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Morrison's climate compare?
Morrison is warmer than 11 of the other 143 places with their own NOAA record in Illinois, and wetter than 37. Across the 7,247 U.S. stations with normals, its annual mean of 48.3°F is warmer than 33%.
In the Köppen classification computed from these normals, Morrison 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 Morrison share this climate record?
5 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.
- Prophetstown, IL1,906 people · 9 mi S
- Como, IL581 people · 11 mi E
- Lyndon, IL529 people · 6 mi SE
- Galt, IL163 people · 11 mi E
- Coleta, IL161 people · 11 mi NE
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 Morrison's climate
What is the coldest month in Morrison?
January, with a normal high of 29°F and a normal low of 12°F. The warmest is July (83°F by day, 62°F at night).
Does it snow in Morrison?
Yes: 32 inches in a normal year, falling on 15 days with 0.1 inch or more, the most in January (10.4 inches).
What is the rainiest month in Morrison?
June, with 4.93 in of precipitation in a normal year; the driest is January with 1.51 in.
What plant hardiness zone is Morrison in?
The USDA's 2023 map puts Morrison in zone 5b in ZIP code 61270, the nearest ZIP area. By the same method at Morrison's NOAA station, the coldest night of a typical year reaches −15°F (29 years, 1991-2020): zone 5a.
How late can frost come in Morrison?
In half of years the last 32°F night comes after April 26; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Fulton, IL12 miles from this station, 49.9°F a year
- Clinton, IA16 miles from this station, 50.2°F a year
- Mount Carroll, IL21 miles from this station, 48.5°F a year
- Dixon, IL24 miles from this station, 49.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made