Quincy, Illinois climate: Normal weather by month, frost dates and records
Quincy's normal year runs from 19°F January nights to 86°F July afternoons, with 36.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.7°C, January lows of −7°C, July highs of 30°C, 925 mm of precipitation a year.
- NOAA stationQuincy Regional Airport
- Station IDUSW00093989
- Location39.94°N 91.19°W
- Elevation769 ft (234 m)
- From the center10 miles
- Population38,786
On October 23, the normal high in Quincy is 62°F and the normal low 42°F, and the chance of measurable rain or snow is 28%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Quincy.
- Jan 35° 19°
- Feb 40° 23°
- Mar 52° 32°
- Apr 64° 43°
- May 73° 54°
- Jun 82° 63°
- Jul 86° 67°
- Aug 85° 65°
- Sep 78° 56°
- Oct 65° 45°
- Nov 51° 33°
- Dec 39° 24°
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 Quincy each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 19°F. The most precipitation falls in May (4.55 in), the least in January (1.57 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 35°F | 19°F | 26.6°F | 1.57 | 8 | <1 | 27 | 9 h 40 min |
| February | 40°F | 23°F | 31.2°F | 1.77 | 7 | <1 | 23 | 10 h 40 min |
| March | 52°F | 32°F | 42.1°F | 2.29 | 10 | <1 | 16 | 11 h 50 min |
| April | 64°F | 43°F | 53.3°F | 3.98 | 12 | <1 | 4 | 13 h 10 min |
| May | 73°F | 54°F | 63.6°F | 4.55 | 13 | 1 | <1 | 14 h 20 min |
| June | 82°F | 63°F | 72.8°F | 4.50 | 10 | 5 | <1 | 15 h |
| July | 86°F | 67°F | 76.3°F | 3.49 | 9 | 9 | <1 | 14 h 50 min |
| August | 85°F | 65°F | 74.5°F | 3.93 | 8 | 7 | <1 | 13 h 50 min |
| September | 78°F | 56°F | 67.0°F | 3.09 | 8 | 3 | <1 | 12 h 30 min |
| October | 65°F | 45°F | 55.1°F | 3.05 | 9 | <1 | 3 | 11 h 10 min |
| November | 51°F | 33°F | 42.3°F | 2.41 | 8 | <1 | 14 | 10 h |
| December | 39°F | 24°F | 31.6°F | 1.80 | 7 | <1 | 25 | 9 h 20 min |
| Year (annual) | 63°F | 44°F | 53.0°F | 36.43 | 109 | 24 | 112 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 1°C | −7°C | −3.0°C | 40 mm |
| February | 4°C | −5°C | −0.4°C | 45 mm |
| March | 11°C | 0°C | 5.6°C | 58 mm |
| April | 18°C | 6°C | 11.8°C | 101 mm |
| May | 23°C | 12°C | 17.6°C | 116 mm |
| June | 28°C | 17°C | 22.7°C | 114 mm |
| July | 30°C | 19°C | 24.6°C | 89 mm |
| August | 29°C | 18°C | 23.6°C | 100 mm |
| September | 26°C | 13°C | 19.4°C | 78 mm |
| October | 19°C | 7°C | 12.8°C | 77 mm |
| November | 11°C | 1°C | 5.7°C | 61 mm |
| December | 4°C | −5°C | −0.2°C | 46 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Perry (22 miles away), gets 21 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093989; 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 Quincy?
Normal highs sit between 65°F and 85°F in May, June, August, September and October. 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 USW00093989.
When is the last frost in Quincy?
In Quincy, the last spring frost (32°F) comes after April 14 in half of years and after May 1 in one year in ten; the first autumn frost comes before October 23 in half of years and before October 10 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 141 year in 10 after May 1; 9 in 10 after March 30
- First autumn frost, half of years before
- October 231 year in 10 before October 10; 9 in 10 before November 4
NOAA puts the median frost-free season at 191 days, and the season without a hard freeze (28°F) at 212 days.
A hard freeze (28°F) comes after April 4 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Quincy in zone 6a in ZIP code 62301. By the map's own method, the average of each year's coldest night over 1991-2020, Quincy's NOAA station is in zone 6a: the coldest night of a typical year reaches −7°F (30 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 USW00093989; 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 Quincy?
In a normal year in Quincy, 24 days a year reach 90°F (1 of them 100°F or more), 112 nights fall to 32°F or colder and 109 days bring measurable precipitation.
- Days at 90°F or more
- 24a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 112a normal year
- Days that stay below freezing
- 34high of 32°F or less
- Days with 0.01 inch of precipitation
- 109a normal year
The highest temperature in Quincy's official record (kept by the National Weather Service since 1901) is 114°F, on July 15, 1936; the lowest is −29°F, on February 13, 1905.
The wettest calendar year on that record is 1973, with 66.60 in; the snowiest season is 1925–26, with 47.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00093989; records: ACIS (NOAA Regional Climate Centers), NWS threaded record UINthr. Records use complete months only; a month missing more than three days is left out.
How sunny is Quincy?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Quincy, 4.2 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 66% | 2.0 |
| February | 68% | 2.9 |
| March | 68% | 3.8 |
| April | 71% | 5.0 |
| May | 73% | 5.7 |
| June | 79% | 6.4 |
| July | 82% | 6.4 |
| August | 81% | 5.6 |
| September | 82% | 4.8 |
| October | 75% | 3.3 |
| November | 72% | 2.3 |
| December | 65% | 1.8 |
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 Quincy need?
A normal year in Quincy brings 5,486 heating degree days, 2% more than the median U.S. place (5,373), and 1,153 cooling degree days, 27% 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 3,691 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,190 | 0 |
| February | 946 | 0 |
| March | 714 | 2 |
| April | 367 | 14 |
| May | 130 | 87 |
| June | 13 | 245 |
| July | 1 | 350 |
| August | 4 | 298 |
| September | 73 | 133 |
| October | 331 | 23 |
| November | 682 | 1 |
| December | 1,035 | 0 |
| Year (annual) | 5,486 | 1,153 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093989. 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 Quincy been warmer than normal lately?
2025 averaged 54.5°F, 1.5°F above the 1991-2020 normal of 53.0°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 54.4°F | +1.4°F | – |
| 2022 | 52.6°F | −0.4°F | 31.26 |
| 2023 | 55.8°F | +2.8°F | 22.62 |
| 2024 | 56.5°F | +3.5°F | 34.38 |
| 2025 | 54.5°F | +1.5°F | 25.98 |
Over 72 complete years from 1950 to 2025, the station's annual mean temperature rose at a fitted 3.8°F per century (+0.21°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00093989; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Quincy's climate compare?
Quincy is warmer than 94 of the other 143 places with their own NOAA record in Illinois, and wetter than 8. Across the 7,247 U.S. stations with normals, its annual mean of 53.0°F is warmer than 54%.
In the Köppen classification computed from these normals, Quincy 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 Quincy share this climate record?
6 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.
- Liberty, IL523 people · 6 mi SE
- Coatsburg, IL149 people · 7 mi N
- Columbus, IL109 people · 4 mi NE
- Paloma, IL104 people · 6 mi N
- Fowler, IL96 people · 6 mi NW
- Burton, IL90 people · 4 mi SW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Quincy's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Quincy. This page uses Quincy Regional Airport; the other differs by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Quincy Dam 21 USC00117077 | 3 mi SW | 483 ft | 53.7°F | 19°F | 87°F | 36.5 | – | April 8 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Quincy's climate
What is the coldest month in Quincy?
January, with a normal high of 35°F and a normal low of 19°F. The warmest is July (86°F by day, 67°F at night).
Does it snow in Quincy?
Yes. NOAA publishes no 1991-2020 snowfall normal for Quincy's NOAA station; the nearest record that keeps one, Perry (22 miles away), records 21 inches of snow in a normal year.
What is the rainiest month in Quincy?
May, with 4.55 in of precipitation in a normal year; the driest is January with 1.57 in.
What plant hardiness zone is Quincy in?
The USDA's 2023 map puts Quincy in zone 6a in ZIP code 62301. By the same method at Quincy's NOAA station, the coldest night of a typical year reaches −7°F (30 years, 1991-2020): zone 6a.
How late can frost come in Quincy?
In half of years the last 32°F night comes after April 14; in one year in ten it comes after May 1. Waiting until May 1 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Quincy in OctoberThis month day by day, its records and recent years
- Illinois climateThe statewide normals and every place in the state
- Golden, IL15 miles from this station, 52.0°F a year
- Hannibal, MO17 miles from this station, 53.0°F a year
- Saverton, MO21 miles from this station, 55.0°F a year
- Perry, IL22 miles from this station, 53.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made