Dixon, Illinois climate: Normal weather by month, frost dates and records
Dixon's normal year runs from 14°F January nights to 83°F July afternoons, with 40.5 inches of precipitation and 31 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.7°C, January lows of −10°C, July highs of 28°C, 1,029 mm of precipitation a year.
- NOAA stationDixon (1 mi W)
- Station IDUSC00112348
- Location41.84°N 89.51°W
- Elevation660 ft (201 m)
- From the center2 miles
- Population15,156
On October 23, the normal high in Dixon is 60°F and the normal low 40°F, and the chance of measurable rain or snow is 23%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Dixon.
- Jan 29° 14°
- Feb 34° 17°
- Mar 46° 28°
- Apr 60° 39°
- May 71° 51°
- Jun 80° 61°
- Jul 83° 64°
- Aug 81° 62°
- Sep 75° 54°
- Oct 63° 42°
- Nov 48° 31°
- Dec 35° 20°
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 Dixon each month?
July is the warmest month, with normal highs of 83°F; January the coldest, with normal lows of 14°F. The most precipitation falls in June (5.59 in), the least in February (1.81 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 29°F | 14°F | 21.3°F | 1.97 | 13.0 | 8 | <1 | 29 | 9 h 30 min |
| February | 34°F | 17°F | 25.5°F | 1.81 | 5.7 | 7 | <1 | 26 | 10 h 30 min |
| March | 46°F | 28°F | 37.3°F | 2.63 | 4.5 | 7 | <1 | 22 | 11 h 50 min |
| April | 60°F | 39°F | 49.4°F | 3.98 | 0.6 | 10 | <1 | 8 | 13 h 20 min |
| May | 71°F | 51°F | 60.9°F | 4.82 | 0.0 | 11 | 1 | 1 | 14 h 30 min |
| June | 80°F | 61°F | 70.2°F | 5.59 | 0.0 | 9 | 3 | <1 | 15 h 10 min |
| July | 83°F | 64°F | 73.5°F | 4.29 | 0.0 | 8 | 4 | <1 | 15 h |
| August | 81°F | 62°F | 71.9°F | 4.19 | 0.0 | 8 | 2 | <1 | 14 h |
| September | 75°F | 54°F | 64.6°F | 3.69 | 0.0 | 7 | 2 | <1 | 12 h 30 min |
| October | 63°F | 42°F | 52.4°F | 2.96 | 0.0 | 7 | <1 | 6 | 11 h 10 min |
| November | 48°F | 31°F | 39.0°F | 2.43 | 1.8 | 7 | <1 | 19 | 9 h 50 min |
| December | 35°F | 20°F | 27.3°F | 2.17 | 5.6 | 8 | <1 | 27 | 9 h 10 min |
| Year (annual) | 59°F | 40°F | 49.4°F | 40.53 | 31.2 | 97 | 11 | 138 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −10°C | −5.9°C | 50 mm | 33 cm |
| February | 1°C | −8°C | −3.6°C | 46 mm | 14 cm |
| March | 8°C | −2°C | 2.9°C | 67 mm | 11 cm |
| April | 16°C | 4°C | 9.7°C | 101 mm | 2 cm |
| May | 22°C | 10°C | 16.1°C | 122 mm | 0 cm |
| June | 27°C | 16°C | 21.2°C | 142 mm | 0 cm |
| July | 28°C | 18°C | 23.1°C | 109 mm | 0 cm |
| August | 27°C | 17°C | 22.2°C | 106 mm | 0 cm |
| September | 24°C | 12°C | 18.1°C | 94 mm | 0 cm |
| October | 17°C | 6°C | 11.3°C | 75 mm | 0 cm |
| November | 9°C | −1°C | 3.9°C | 62 mm | 5 cm |
| December | 1°C | −7°C | −2.6°C | 55 mm | 14 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00112348; 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 Dixon?
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 USC00112348.
When is the last frost in Dixon?
In Dixon, the last spring frost (32°F) comes after April 21 in half of years and after May 5 in one year in ten; the first autumn frost comes before October 19 in half of years and before October 4 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 211 year in 10 after May 5; 9 in 10 after April 7
- First autumn frost, half of years before
- October 191 year in 10 before October 4; 9 in 10 before October 30
NOAA puts the median frost-free season at 180 days, and the season without a hard freeze (28°F) at 201 days.
A hard freeze (28°F) comes after April 10 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Dixon in zone 5b in ZIP code 61021, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Dixon's NOAA station is in zone 5a: the coldest night of a typical year reaches −15°F (23 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 USC00112348; 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 Dixon?
In a normal year in Dixon, 11 days a year reach 90°F, 138 nights fall to 32°F or colder and 97 days bring measurable precipitation.
- Days at 90°F or more
- 11a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 138a normal year
- Days that stay below freezing
- 48high of 32°F or less
- Days with 0.01 inch of precipitation
- 97a normal year
- Days with 1 inch of snow or more
- 11a normal year
The highest temperature in this station's record (since 1893) is 110°F, on July 14, 1936; the lowest is −32°F, on January 17, 2009.
The wettest calendar year on that record is 2018, with 51.27 in; the snowiest season is 1978–79, with 92.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00112348; records: ACIS (NOAA Regional Climate Centers), station USC00112348. Records use complete months only; a month missing more than three days is left out.
How sunny is Dixon?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Dixon, 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 Dixon need?
A normal year in Dixon brings 6,487 heating degree days, 21% more than the median U.S. place (5,373), and 852 cooling degree days, 6% 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 3,126 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,355 | 0 |
| February | 1,107 | 0 |
| March | 860 | 1 |
| April | 476 | 7 |
| May | 189 | 60 |
| June | 30 | 188 |
| July | 4 | 267 |
| August | 9 | 223 |
| September | 107 | 93 |
| October | 404 | 13 |
| November | 779 | 0 |
| December | 1,169 | 0 |
| Year (annual) | 6,487 | 852 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00112348. 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 Dixon been warmer than normal lately?
2025 averaged 50.2°F, 0.8°F above the 1991-2020 normal of 49.4°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 50.3°F | +0.9°F | 28.48 | 31.4 |
| 2022 | 48.2°F | −1.2°F | 39.79 | 17.9 |
| 2023 | 51.2°F | +1.8°F | 37.30 | 22.4 |
| 2024 | 52.2°F | +2.8°F | 33.54 | 15.5 |
| 2025 | 50.2°F | +0.8°F | 33.65 | 28.0 |
Over 101 complete years from 1882 to 2025, the station's annual mean temperature rose at a fitted 2.1°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 USC00112348; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Dixon's climate compare?
Dixon is warmer than 25 of the other 143 places with their own NOAA record in Illinois, and wetter than 84. Across the 7,247 U.S. stations with normals, its annual mean of 49.4°F is warmer than 38%.
In the Köppen classification computed from these normals, Dixon 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 Dixon share this climate record?
9 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.
- Sterling, IL14,535 people · 10 mi W
- Rock Falls, IL8,614 people · 10 mi SW
- Amboy, IL2,224 people · 12 mi SE
- Franklin Grove, IL876 people · 11 mi E
- Lost Nation, IL727 people · 9 mi NE
- Grand Detour, IL282 people · 7 mi NE
- Nelson, IL125 people · 6 mi SW
- Nachusa, IL123 people · 7 mi E
- Harmon, IL117 people · 8 mi S
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 Dixon's climate
What is the coldest month in Dixon?
January, with a normal high of 29°F and a normal low of 14°F. The warmest is July (83°F by day, 64°F at night).
Does it snow in Dixon?
Yes: 31 inches in a normal year, falling on 17 days with 0.1 inch or more, the most in January (13.0 inches).
What is the rainiest month in Dixon?
June, with 5.59 in of precipitation in a normal year; the driest is February with 1.81 in.
What plant hardiness zone is Dixon in?
The USDA's 2023 map puts Dixon in zone 5b in ZIP code 61021, the nearest ZIP area. By the same method at Dixon's NOAA station, the coldest night of a typical year reaches −15°F (23 years, 1991-2020): zone 5a.
How late can frost come in Dixon?
In half of years the last 32°F night comes after April 21; in one year in ten it comes after May 5. Waiting until May 5 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Polo, IL14 miles from this station, 49.3°F a year
- Walnut, IL19 miles from this station, 49.3°F a year
- Compton, IL23 miles from this station, 48.2°F a year
- Rochelle, IL24 miles from this station, 47.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made