Fulton, Illinois climate: Normal weather by month, frost dates and records
Fulton's normal year runs from 14°F January nights to 84°F July afternoons, with 34.3 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.9°C, January lows of −10°C, July highs of 29°C, 870 mm of precipitation a year.
- NOAA stationFulton Lock and Dam #13
- Station IDUSC00113290
- Location41.90°N 90.15°W
- Elevation592 ft (180 m)
- Population3,581
On October 14, the normal high in Fulton is 64°F and the normal low 44°F, and the chance of measurable rain or snow is 25%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fulton.
- Jan 29° 14°
- Feb 34° 17°
- Mar 46° 28°
- Apr 59° 40°
- May 71° 51°
- Jun 81° 62°
- Jul 84° 65°
- Aug 82° 63°
- Sep 76° 55°
- Oct 63° 43°
- Nov 48° 31°
- Dec 35° 21°
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 Fulton each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 14°F. The most precipitation falls in June (4.52 in), the least in January (1.40 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 29°F | 14°F | 21.4°F | 1.40 | 7 | <1 | 30 | 9 h 30 min |
| February | 34°F | 17°F | 25.4°F | 1.56 | 6 | <1 | 26 | 10 h 30 min |
| March | 46°F | 28°F | 36.9°F | 2.41 | 8 | <1 | 22 | 11 h 50 min |
| April | 59°F | 40°F | 49.6°F | 3.39 | 10 | <1 | 6 | 13 h 20 min |
| May | 71°F | 51°F | 61.2°F | 4.03 | 11 | 1 | <1 | 14 h 30 min |
| June | 81°F | 62°F | 71.2°F | 4.52 | 11 | 3 | <1 | 15 h 10 min |
| July | 84°F | 65°F | 74.6°F | 3.40 | 8 | 5 | <1 | 15 h |
| August | 82°F | 63°F | 72.7°F | 3.43 | 8 | 3 | <1 | 14 h |
| September | 76°F | 55°F | 65.5°F | 3.66 | 8 | 1 | <1 | 12 h 30 min |
| October | 63°F | 43°F | 53.2°F | 2.58 | 8 | <1 | 3 | 11 h 10 min |
| November | 48°F | 31°F | 39.5°F | 2.20 | 7 | <1 | 18 | 9 h 50 min |
| December | 35°F | 21°F | 27.7°F | 1.69 | 7 | <1 | 28 | 9 h 10 min |
| Year (annual) | 59°F | 41°F | 49.9°F | 34.27 | 98 | 13 | 132 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −1°C | −10°C | −5.9°C | 36 mm |
| February | 1°C | −8°C | −3.7°C | 40 mm |
| March | 8°C | −2°C | 2.7°C | 61 mm |
| April | 15°C | 4°C | 9.8°C | 86 mm |
| May | 22°C | 11°C | 16.2°C | 102 mm |
| June | 27°C | 17°C | 21.8°C | 115 mm |
| July | 29°C | 18°C | 23.7°C | 86 mm |
| August | 28°C | 17°C | 22.6°C | 87 mm |
| September | 24°C | 13°C | 18.6°C | 93 mm |
| October | 17°C | 6°C | 11.8°C | 66 mm |
| November | 9°C | 0°C | 4.2°C | 56 mm |
| December | 2°C | −6°C | −2.4°C | 43 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Clinton (9 miles away), gets 32 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00113290; 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 Fulton?
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 USC00113290.
When is the last frost in Fulton?
In Fulton, the last spring frost (32°F) comes after April 13 in half of years and after April 28 in one year in ten; the first autumn frost comes before October 26 in half of years and before October 13 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 131 year in 10 after April 28; 9 in 10 after April 1
- First autumn frost, half of years before
- October 261 year in 10 before October 13; 9 in 10 before November 7
NOAA puts the median frost-free season at 195 days, and the season without a hard freeze (28°F) at 214 days.
A hard freeze (28°F) comes after April 4 in half of springs and before November 3 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fulton in zone 5b in ZIP code 61252, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Fulton's NOAA station is in zone 5b: the coldest night of a typical year reaches −13°F (23 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 USC00113290; 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 Fulton?
In a normal year in Fulton, 13 days a year reach 90°F, 132 nights fall to 32°F or colder and 98 days bring measurable precipitation.
- Days at 90°F or more
- 13a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 132a normal year
- Days that stay below freezing
- 50high of 32°F or less
- Days with 0.01 inch of precipitation
- 98a normal year
The highest temperature in this station's record (since 1938) is 102°F, on July 25, 2005; the lowest is −33°F, on January 16, 2009.
The wettest calendar year on that record is 2019, with 53.63 in; the snowiest season is 1959–60, with 66.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00113290; records: ACIS (NOAA Regional Climate Centers), station USC00113290. Records use complete months only; a month missing more than three days is left out.
How sunny is Fulton?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fulton, 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 | 70% | 2.8 |
| March | 69% | 3.7 |
| April | 70% | 4.8 |
| May | 72% | 5.5 |
| June | 77% | 6.2 |
| July | 81% | 6.3 |
| August | 80% | 5.5 |
| September | 81% | 4.5 |
| October | 72% | 3.0 |
| November | 69% | 2.1 |
| 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 Fulton need?
A normal year in Fulton brings 6,394 heating degree days, 19% more than the median U.S. place (5,373), and 937 cooling degree days, 3% 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 3,245 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,350 | 0 |
| February | 1,107 | 0 |
| March | 871 | 1 |
| April | 468 | 6 |
| May | 175 | 59 |
| June | 25 | 211 |
| July | 3 | 300 |
| August | 6 | 243 |
| September | 88 | 105 |
| October | 378 | 12 |
| November | 765 | 0 |
| December | 1,158 | 0 |
| Year (annual) | 6,394 | 937 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00113290. 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 Fulton been warmer than normal lately?
2024 averaged 53.4°F, 3.5°F above the 1991-2020 normal of 49.9°F. 2 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 51.1°F | +1.3°F | 27.34 |
| 2022 | 49.2°F | −0.7°F | 37.71 |
| 2024 | 53.4°F | +3.5°F | 33.32 |
Over 68 complete years from 1942 to 2025, the station's annual mean temperature rose at a fitted 1.7°F per century (+0.09°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00113290; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Fulton's climate compare?
Fulton is warmer than 35 of the other 143 places with their own NOAA record in Illinois, and wetter than 2. Across the 7,247 U.S. stations with normals, its annual mean of 49.9°F is warmer than 40%.
In the Köppen classification computed from these normals, Fulton 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 Fulton 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.
- DeWitt, IA5,620 people · 21 mi W
- Camanche, IA4,536 people · 10 mi SW
- Preston, IA940 people · 16 mi NW
- Miles, IA400 people · 13 mi NW
- Charlotte, IA386 people · 17 mi W
- Goose Lake, IA250 people · 13 mi W
- Low Moor, IA242 people · 12 mi SW
- Andover, IA106 people · 8 mi NW
- Spragueville, IA92 people · 19 mi NW
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 Fulton's climate
What is the coldest month in Fulton?
January, with a normal high of 29°F and a normal low of 14°F. The warmest is July (84°F by day, 65°F at night).
Does it snow in Fulton?
Yes. NOAA publishes no 1991-2020 snowfall normal for Fulton's NOAA station; the nearest record that keeps one, Clinton (9 miles away), records 32 inches of snow in a normal year.
What is the rainiest month in Fulton?
June, with 4.52 in of precipitation in a normal year; the driest is January with 1.40 in.
What plant hardiness zone is Fulton in?
The USDA's 2023 map puts Fulton in zone 5b in ZIP code 61252, the nearest ZIP area. By the same method at Fulton's NOAA station, the coldest night of a typical year reaches −13°F (23 years, 1991-2020): zone 5b.
How late can frost come in Fulton?
In half of years the last 32°F night comes after April 13; in one year in ten it comes after April 28. Waiting until April 28 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Clinton, IA9 miles from this station, 50.2°F a year
- Morrison, IL12 miles from this station, 48.3°F a year
- Mount Carroll, IL16 miles from this station, 48.5°F a year
- Le Claire, IA25 miles from this station, 50.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made