Rochelle, Illinois climate: Normal weather by month, frost dates and records
Rochelle's normal year runs from 12°F January nights to 82°F July afternoons, with 36.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.8°C, January lows of −11°C, July highs of 28°C, 929 mm of precipitation a year.
- NOAA stationRochelle
- Station IDUSC00117354
- Location41.91°N 89.07°W
- Elevation775 ft (236 m)
- Population9,510
On October 22, the normal high in Rochelle is 59°F and the normal low 38°F, and the chance of measurable rain or snow is 29%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Rochelle.
- Jan 28° 12°
- Feb 32° 16°
- Mar 45° 26°
- Apr 59° 37°
- May 70° 48°
- Jun 79° 59°
- Jul 82° 61°
- Aug 81° 60°
- Sep 75° 52°
- Oct 62° 40°
- Nov 47° 29°
- Dec 34° 18°
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 Rochelle each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 12°F. The most precipitation falls in June (4.92 in), the least in February (1.70 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 28°F | 12°F | 20.1°F | 1.78 | 9 | <1 | 30 | 9 h 30 min |
| February | 32°F | 16°F | 23.8°F | 1.70 | 8 | <1 | 26 | 10 h 30 min |
| March | 45°F | 26°F | 35.6°F | 2.27 | 9 | <1 | 24 | 11 h 50 min |
| April | 59°F | 37°F | 47.6°F | 3.44 | 11 | <1 | 9 | 13 h 20 min |
| May | 70°F | 48°F | 59.0°F | 4.69 | 13 | 1 | 1 | 14 h 30 min |
| June | 79°F | 59°F | 68.9°F | 4.92 | 11 | 3 | <1 | 15 h 10 min |
| July | 82°F | 61°F | 71.8°F | 3.55 | 9 | 4 | <1 | 15 h |
| August | 81°F | 60°F | 70.2°F | 3.92 | 9 | 2 | <1 | 14 h |
| September | 75°F | 52°F | 63.4°F | 3.26 | 8 | 1 | <1 | 12 h 30 min |
| October | 62°F | 40°F | 51.0°F | 2.81 | 9 | <1 | 7 | 11 h 10 min |
| November | 47°F | 29°F | 37.7°F | 2.30 | 8 | <1 | 20 | 9 h 50 min |
| December | 34°F | 18°F | 26.0°F | 1.95 | 9 | <1 | 28 | 9 h 10 min |
| Year (annual) | 58°F | 38°F | 47.9°F | 36.59 | 111 | 11 | 145 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −2°C | −11°C | −6.6°C | 45 mm |
| February | 0°C | −9°C | −4.6°C | 43 mm |
| March | 7°C | −3°C | 2.0°C | 58 mm |
| April | 15°C | 3°C | 8.7°C | 87 mm |
| May | 21°C | 9°C | 15.0°C | 119 mm |
| June | 26°C | 15°C | 20.5°C | 125 mm |
| July | 28°C | 16°C | 22.1°C | 90 mm |
| August | 27°C | 15°C | 21.2°C | 100 mm |
| September | 24°C | 11°C | 17.4°C | 83 mm |
| October | 17°C | 4°C | 10.6°C | 71 mm |
| November | 8°C | −2°C | 3.2°C | 58 mm |
| December | 1°C | −8°C | −3.3°C | 50 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, DeKalb (15 miles away), gets 33 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00117354; 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 Rochelle?
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 USC00117354.
When is the last frost in Rochelle?
In Rochelle, the last spring frost (32°F) comes after April 26 in half of years and after May 12 in one year in ten; the first autumn frost comes before October 13 in half of years and before September 29 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 261 year in 10 after May 12; 9 in 10 after April 11
- First autumn frost, half of years before
- October 131 year in 10 before September 29; 9 in 10 before October 25
NOAA puts the median frost-free season at 168 days, and the season without a hard freeze (28°F) at 191 days.
A hard freeze (28°F) comes after April 14 in half of springs and before October 24 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Rochelle in zone 5b in ZIP code 61068. By the map's own method, the average of each year's coldest night over 1991-2020, Rochelle's NOAA station is in zone 5b: the coldest night of a typical year reaches −15°F (27 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 USC00117354; 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 Rochelle?
In a normal year in Rochelle, 11 days a year reach 90°F, 145 nights fall to 32°F or colder and 111 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
- 145a normal year
- Days that stay below freezing
- 54high of 32°F or less
- Days with 0.01 inch of precipitation
- 111a normal year
The highest temperature in this station's record (since 1940) is 101°F, on June 26, 1988; the lowest is −33°F, on January 19, 1985.
The wettest calendar year on that record is 2008, with 49.57 in; the snowiest season is 1925–26, with 53.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00117354; records: ACIS (NOAA Regional Climate Centers), station USC00117354. Records use complete months only; a month missing more than three days is left out.
How sunny is Rochelle?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Rochelle, 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 Rochelle need?
A normal year in Rochelle brings 6,875 heating degree days, 28% more than the median U.S. place (5,373), and 692 cooling degree days, 24% 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 2,833 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,392 | 0 |
| February | 1,153 | 0 |
| March | 912 | 1 |
| April | 524 | 3 |
| May | 231 | 46 |
| June | 39 | 154 |
| July | 10 | 221 |
| August | 17 | 179 |
| September | 127 | 78 |
| October | 443 | 9 |
| November | 819 | 0 |
| December | 1,209 | 0 |
| Year (annual) | 6,875 | 692 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00117354. 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 Rochelle been warmer than normal lately?
Over 30 complete years from 1980 to 2016, 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: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Rochelle's climate compare?
Rochelle is warmer than 6 of the other 143 places with their own NOAA record in Illinois, and wetter than 10. Across the 7,247 U.S. stations with normals, its annual mean of 47.9°F is warmer than 31%.
In the Köppen classification computed from these normals, Rochelle 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 Rochelle 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.
- Hillcrest, IL1,206 people · 4 mi N
- Ashton, IL939 people · 8 mi W
- Creston, IL618 people · 5 mi E
- Kings, IL322 people · 7 mi N
- Steward, IL223 people · 5 mi SE
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 Rochelle's climate
What is the coldest month in Rochelle?
January, with a normal high of 28°F and a normal low of 12°F. The warmest is July (82°F by day, 61°F at night).
Does it snow in Rochelle?
Yes. NOAA publishes no 1991-2020 snowfall normal for Rochelle's NOAA station; the nearest record that keeps one, DeKalb (15 miles away), records 33 inches of snow in a normal year.
What is the rainiest month in Rochelle?
June, with 4.92 in of precipitation in a normal year; the driest is February with 1.70 in.
What plant hardiness zone is Rochelle in?
The USDA's 2023 map puts Rochelle in zone 5b in ZIP code 61068. By the same method at Rochelle's NOAA station, the coldest night of a typical year reaches −15°F (27 years, 1991-2020): zone 5b.
How late can frost come in Rochelle?
In half of years the last 32°F night comes after April 26; in one year in ten it comes after May 12. Waiting until May 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Shabbona, IL12 miles from this station, 47.8°F a year
- Compton, IL14 miles from this station, 48.2°F a year
- DeKalb, IL16 miles from this station, 48.6°F a year
- Paw Paw, IL17 miles from this station, 47.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made