Rosiclare, Illinois climate: Normal weather by month, frost dates and records
Rosiclare's normal year runs from 22°F January nights to 86°F July afternoons, with 50.9 inches of precipitation and 3 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.7°C, January lows of −5°C, July highs of 30°C, 1,293 mm of precipitation a year.
- NOAA stationRosiclare (5 mi NW)
- Station IDUSC00117487
- Location37.47°N 88.41°W
- Elevation400 ft (122 m)
- From the center5 miles
- Population955
On October 23, the normal high in Rosiclare is 66°F and the normal low 40°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Rosiclare.
- Jan 41° 22°
- Feb 46° 25°
- Mar 56° 33°
- Apr 68° 43°
- May 75° 53°
- Jun 83° 62°
- Jul 86° 65°
- Aug 86° 63°
- Sep 80° 55°
- Oct 69° 43°
- Nov 56° 33°
- Dec 45° 26°
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 Rosiclare each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 22°F. The most precipitation falls in May (5.35 in), the least in August (3.24 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 41°F | 22°F | 31.8°F | 3.90 | 0.9 | 10 | <1 | 25 | 9 h 50 min |
| February | 46°F | 25°F | 35.7°F | 3.71 | 1.4 | 9 | <1 | 21 | 10 h 50 min |
| March | 56°F | 33°F | 44.8°F | 5.08 | 0.2 | 12 | <1 | 15 | 11 h 50 min |
| April | 68°F | 43°F | 55.1°F | 5.12 | 0.0 | 11 | <1 | 5 | 13 h 10 min |
| May | 75°F | 53°F | 63.9°F | 5.35 | 0.0 | 11 | <1 | <1 | 14 h 10 min |
| June | 83°F | 62°F | 72.3°F | 4.61 | 0.0 | 9 | 5 | <1 | 14 h 40 min |
| July | 86°F | 65°F | 75.8°F | 4.40 | 0.0 | 9 | 11 | <1 | 14 h 30 min |
| August | 86°F | 63°F | 74.5°F | 3.24 | 0.0 | 7 | 10 | <1 | 13 h 40 min |
| September | 80°F | 55°F | 67.8°F | 3.24 | 0.0 | 7 | 4 | <1 | 12 h 30 min |
| October | 69°F | 43°F | 56.0°F | 3.57 | 0.2 | 8 | <1 | 5 | 11 h 20 min |
| November | 56°F | 33°F | 44.6°F | 4.23 | 0.0 | 9 | <1 | 15 | 10 h 10 min |
| December | 45°F | 26°F | 35.8°F | 4.44 | 0.6 | 10 | <1 | 23 | 9 h 40 min |
| Year (annual) | 66°F | 44°F | 54.8°F | 50.89 | 3.3 | 110 | 31 | 109 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | −5°C | −0.1°C | 99 mm | 2 cm |
| February | 8°C | −4°C | 2.1°C | 94 mm | 4 cm |
| March | 13°C | 1°C | 7.1°C | 129 mm | 1 cm |
| April | 20°C | 6°C | 12.8°C | 130 mm | 0 cm |
| May | 24°C | 11°C | 17.7°C | 136 mm | 0 cm |
| June | 28°C | 16°C | 22.4°C | 117 mm | 0 cm |
| July | 30°C | 18°C | 24.3°C | 112 mm | 0 cm |
| August | 30°C | 17°C | 23.6°C | 82 mm | 0 cm |
| September | 27°C | 13°C | 19.9°C | 82 mm | 0 cm |
| October | 21°C | 6°C | 13.3°C | 91 mm | 1 cm |
| November | 13°C | 1°C | 7.0°C | 107 mm | 0 cm |
| December | 7°C | −3°C | 2.1°C | 113 mm | 2 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00117487; 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 Rosiclare?
Normal highs sit between 65°F and 85°F in April, 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 USC00117487.
When is the last frost in Rosiclare?
In Rosiclare, the last spring frost (32°F) comes after April 19 in half of years and after May 8 in one year in ten; the first autumn frost comes before October 20 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 191 year in 10 after May 8; 9 in 10 after April 3
- First autumn frost, half of years before
- October 201 year in 10 before October 7; 9 in 10 before October 30
NOAA puts the median frost-free season at 181 days, and the season without a hard freeze (28°F) at 204 days.
A hard freeze (28°F) comes after April 6 in half of springs and before October 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Rosiclare in zone 7a in ZIP code 62982. By the map's own method, the average of each year's coldest night over 1991-2020, Rosiclare's NOAA station is in zone 6b: the coldest night of a typical year reaches −1°F (21 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 USC00117487; 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 Rosiclare?
In a normal year in Rosiclare, 31 days a year reach 90°F (1 of them 100°F or more), 109 nights fall to 32°F or colder and 110 days bring measurable precipitation.
- Days at 90°F or more
- 31a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 109a normal year
- Days that stay below freezing
- 16high of 32°F or less
- Days with 0.01 inch of precipitation
- 110a normal year
- Days with 1 inch of snow or more
- 1a normal year
The highest temperature in this station's record (since 1968) is 107°F, on June 30, 2012; the lowest is −22°F, on January 19, 1994.
The wettest calendar year on that record is 2018, with 66.19 in; the snowiest season is 1984–85, with 43.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00117487; records: ACIS (NOAA Regional Climate Centers), station USC00117487. Records use complete months only; a month missing more than three days is left out.
How sunny is Rosiclare?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Rosiclare, 4.2 kWh per square metre a day. August is the sunniest month (83%) and December the cloudiest (64%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 2.1 |
| February | 64% | 2.8 |
| March | 67% | 3.8 |
| April | 73% | 5.1 |
| May | 74% | 5.7 |
| June | 82% | 6.5 |
| July | 83% | 6.3 |
| August | 83% | 5.7 |
| September | 81% | 4.8 |
| October | 76% | 3.5 |
| November | 72% | 2.5 |
| December | 64% | 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 Rosiclare need?
A normal year in Rosiclare brings 4,803 heating degree days, 11% fewer than the median U.S. place (5,373), and 1,131 cooling degree days, 25% more than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,804 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,029 | 0 |
| February | 822 | 0 |
| March | 629 | 3 |
| April | 316 | 19 |
| May | 118 | 84 |
| June | 11 | 229 |
| July | 1 | 336 |
| August | 2 | 298 |
| September | 56 | 139 |
| October | 300 | 23 |
| November | 612 | 2 |
| December | 907 | 0 |
| Year (annual) | 4,803 | 1,131 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00117487. 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 Rosiclare been warmer than normal lately?
2021 averaged 55.5°F, 0.7°F above the 1991-2020 normal of 54.8°F.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 55.5°F | +0.7°F | 50.68 | 8.6 |
Over 31 complete years from 1969 to 2021, the station's annual mean temperature rose at a fitted 5.1°F per century (+0.28°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00117487; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Rosiclare's climate compare?
Rosiclare is warmer than 116 of the other 143 places with their own NOAA record in Illinois, and wetter than 135. Across the 7,247 U.S. stations with normals, its annual mean of 54.8°F is warmer than 59%.
In the Köppen classification computed from these normals, Rosiclare 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 Rosiclare 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.
- Marion, KY2,876 people · 21 mi SE
- Golconda, IL623 people · 9 mi SW
- Elizabethtown, IL223 people · 6 mi E
- Carrsville, KY44 people · 6 mi S
- Tolu, KY35 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 Rosiclare's climate
What is the coldest month in Rosiclare?
January, with a normal high of 41°F and a normal low of 22°F. The warmest is July (86°F by day, 65°F at night).
Does it snow in Rosiclare?
Yes: 3 inches in a normal year, falling on 2 days with 0.1 inch or more, the most in February (1.4 inches).
What is the rainiest month in Rosiclare?
May, with 5.35 in of precipitation in a normal year; the driest is August with 3.24 in.
What plant hardiness zone is Rosiclare in?
The USDA's 2023 map puts Rosiclare in zone 7a in ZIP code 62982. By the same method at Rosiclare's NOAA station, the coldest night of a typical year reaches −1°F (21 years, 1991-2020): zone 6b.
How late can frost come in Rosiclare?
In half of years the last 32°F night comes after April 19; in one year in ten it comes after May 8. Waiting until May 8 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Dixon Springs Agricultural Center, IL14 miles from this station, 57.2°F a year
- Harrisburg, IL19 miles from this station, 57.3°F a year
- Smithland Lock and Dam, IL22 miles from this station, 57.1°F a year
- Brookport, IL27 miles from this station, 57.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made