Jerseyville, Illinois climate: Normal weather by month, frost dates and records
Jerseyville's normal year runs from 19°F January nights to 87°F July afternoons, with 42.2 inches of precipitation and 13 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.9°C, January lows of −7°C, July highs of 30°C, 1,072 mm of precipitation a year.
- NOAA stationJerseyville (2 mi SW)
- Station IDUSC00114489
- Location39.10°N 90.34°W
- Elevation630 ft (192 m)
- From the center1 miles
- Population8,350
On October 23, the normal high in Jerseyville is 64°F and the normal low 41°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 Jerseyville.
- Jan 36° 19°
- Feb 42° 23°
- Mar 53° 32°
- Apr 65° 42°
- May 74° 54°
- Jun 83° 63°
- Jul 87° 66°
- Aug 85° 63°
- Sep 79° 55°
- Oct 67° 43°
- Nov 53° 33°
- Dec 41° 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 Jerseyville each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 19°F. The most precipitation falls in May (5.29 in), the least in February (2.31 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 36°F | 19°F | 27.8°F | 2.45 | 4.3 | 8 | <1 | 27 | 9 h 40 min |
| February | 42°F | 23°F | 32.2°F | 2.31 | 3.7 | 7 | <1 | 23 | 10 h 40 min |
| March | 53°F | 32°F | 42.2°F | 3.17 | 1.6 | 10 | <1 | 17 | 11 h 50 min |
| April | 65°F | 42°F | 53.4°F | 4.55 | 0.0 | 11 | <1 | 5 | 13 h 10 min |
| May | 74°F | 54°F | 64.1°F | 5.29 | 0.0 | 12 | 1 | <1 | 14 h 20 min |
| June | 83°F | 63°F | 72.8°F | 4.12 | 0.0 | 9 | 6 | <1 | 14 h 50 min |
| July | 87°F | 66°F | 76.2°F | 3.56 | 0.0 | 8 | 11 | <1 | 14 h 40 min |
| August | 85°F | 63°F | 74.2°F | 3.72 | 0.0 | 7 | 8 | <1 | 13 h 40 min |
| September | 79°F | 55°F | 66.9°F | 3.44 | 0.0 | 7 | 4 | <1 | 12 h 30 min |
| October | 67°F | 43°F | 55.2°F | 3.29 | 0.0 | 8 | <1 | 4 | 11 h 10 min |
| November | 53°F | 33°F | 42.9°F | 3.67 | 0.7 | 9 | <1 | 15 | 10 h |
| December | 41°F | 24°F | 32.7°F | 2.65 | 2.2 | 8 | <1 | 25 | 9 h 30 min |
| Year (annual) | 64°F | 43°F | 53.4°F | 42.22 | 12.5 | 103 | 29 | 118 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −7°C | −2.3°C | 62 mm | 11 cm |
| February | 5°C | −5°C | 0.1°C | 59 mm | 9 cm |
| March | 11°C | 0°C | 5.7°C | 81 mm | 4 cm |
| April | 18°C | 6°C | 11.9°C | 116 mm | 0 cm |
| May | 24°C | 12°C | 17.8°C | 134 mm | 0 cm |
| June | 28°C | 17°C | 22.7°C | 105 mm | 0 cm |
| July | 30°C | 19°C | 24.6°C | 90 mm | 0 cm |
| August | 30°C | 17°C | 23.4°C | 94 mm | 0 cm |
| September | 26°C | 13°C | 19.4°C | 87 mm | 0 cm |
| October | 20°C | 6°C | 12.9°C | 84 mm | 0 cm |
| November | 12°C | 1°C | 6.1°C | 93 mm | 2 cm |
| December | 5°C | −4°C | 0.4°C | 67 mm | 6 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00114489; 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 Jerseyville?
Normal highs sit between 65°F and 85°F in May, June, September and October. 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 USC00114489.
When is the last frost in Jerseyville?
In Jerseyville, the last spring frost (32°F) comes after April 14 in half of years and after April 30 in one year in ten; the first autumn frost comes before October 19 in half of years and before October 7 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 April 30; 9 in 10 after March 31
- First autumn frost, half of years before
- October 191 year in 10 before October 7; 9 in 10 before November 1
NOAA puts the median frost-free season at 187 days, and the season without a hard freeze (28°F) at 208 days.
A hard freeze (28°F) comes after April 4 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Jerseyville in zone 6b in ZIP code 62052, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Jerseyville's NOAA station is in zone 6a: the coldest night of a typical year reaches −5°F (25 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 USC00114489; 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 Jerseyville?
In a normal year in Jerseyville, 29 days a year reach 90°F (1 of them 100°F or more), 118 nights fall to 32°F or colder and 103 days bring measurable precipitation.
- Days at 90°F or more
- 29a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 118a normal year
- Days that stay below freezing
- 27high of 32°F or less
- Days with 0.01 inch of precipitation
- 103a normal year
- Days with 1 inch of snow or more
- 5a normal year
The highest temperature in this station's record (since 1940) is 112°F, on July 15, 1954; the lowest is −25°F, on January 17, 1977.
The wettest calendar year on that record is 2008, with 62.64 in; the snowiest season is 1977–78, with 45.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00114489; records: ACIS (NOAA Regional Climate Centers), station USC00114489. Records use complete months only; a month missing more than three days is left out.
How sunny is Jerseyville?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Jerseyville, 4.1 kWh per square metre a day. July is the sunniest month (83%) and December the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 66% | 2.0 |
| February | 67% | 2.8 |
| March | 68% | 3.7 |
| April | 72% | 4.9 |
| May | 73% | 5.6 |
| June | 80% | 6.3 |
| July | 83% | 6.4 |
| August | 81% | 5.6 |
| September | 82% | 4.8 |
| October | 75% | 3.3 |
| November | 72% | 2.3 |
| December | 65% | 1.7 |
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 Jerseyville need?
A normal year in Jerseyville brings 5,348 heating degree days, 0% fewer than the median U.S. place (5,373), and 1,152 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 3,714 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,154 | 0 |
| February | 920 | 0 |
| March | 710 | 2 |
| April | 362 | 15 |
| May | 121 | 92 |
| June | 14 | 249 |
| July | 1 | 350 |
| August | 4 | 291 |
| September | 70 | 129 |
| October | 326 | 23 |
| November | 664 | 1 |
| December | 1,001 | 0 |
| Year (annual) | 5,348 | 1,152 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00114489. 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 Jerseyville been warmer than normal lately?
2023 averaged 55.4°F, 2.0°F above the 1991-2020 normal of 53.4°F. 2 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 54.4°F | +1.0°F | 41.14 | 6.0 |
| 2022 | 52.9°F | −0.5°F | 39.78 | 17.7 |
| 2023 | 55.4°F | +2.0°F | 30.18 | 4.0 |
Over 54 complete years from 1941 to 2023, the station's annual mean temperature rose at a fitted 1.3°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 USC00114489; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Jerseyville's climate compare?
Jerseyville is warmer than 99 of the other 143 places with their own NOAA record in Illinois, and wetter than 104. Across the 7,247 U.S. stations with normals, its annual mean of 53.4°F is warmer than 55%.
In the Köppen classification computed from these normals, Jerseyville 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 Jerseyville 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.
- Medora, IL364 people · 12 mi NE
- Kane, IL280 people · 6 mi N
- Rockbridge, IL172 people · 14 mi NE
- Fidelity, IL94 people · 10 mi E
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 Jerseyville's climate
What is the coldest month in Jerseyville?
January, with a normal high of 36°F and a normal low of 19°F. The warmest is July (87°F by day, 66°F at night).
Does it snow in Jerseyville?
Yes: 13 inches in a normal year, falling on 7 days with 0.1 inch or more, the most in January (4.3 inches).
What is the rainiest month in Jerseyville?
May, with 5.29 in of precipitation in a normal year; the driest is February with 2.31 in.
What plant hardiness zone is Jerseyville in?
The USDA's 2023 map puts Jerseyville in zone 6b in ZIP code 62052, the nearest ZIP area. By the same method at Jerseyville's NOAA station, the coldest night of a typical year reaches −5°F (25 years, 1991-2020): zone 6a.
How late can frost come in Jerseyville?
In half of years the last 32°F night comes after April 14; in one year in ten it comes after April 30. Waiting until April 30 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- St. Charles, MO13 miles from this station, 56.1°F a year
- Alton, IL19 miles from this station, 55.7°F a year
- White Hall, IL24 miles from this station, 52.9°F a year
- Elsberry, MO24 miles from this station, 54.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made