Climateby Month

Rockford, IL climate by month

NOAA 1991-2020 normals · 717 ft elevation

Summers in Rockford are warm and often humid; winters are very cold and snowy. Highs peak at 84°F in July and fall to 29°F in January. Wet days are spread through the year, from about 8 to 13 a month. Normal snowfall is about 37 in a year. The most comfortable time to visit is May.

Warmest month
84°F
July normal high
Coldest month
15°F
January normal low
Wet days a year
121
37.2 in of precipitation
Snow a year
37.1 in
normal snowfall

How warm is Rockford?

Normal highs range from 29°F in January to 84°F in July.

0°20°40°60°80°100° January: normal high 29°F (-2°C), low 15°F (-9°C) 29° 15° February: normal high 33°F (1°C), low 18°F (-8°C) March: normal high 47°F (8°C), low 28°F (-2°C) April: normal high 60°F (16°C), low 39°F (4°C) May: normal high 71°F (22°C), low 50°F (10°C) June: normal high 81°F (27°C), low 60°F (16°C) July: normal high 84°F (29°C), low 64°F (18°C) 84° 64° August: normal high 82°F (28°C), low 62°F (17°C) September: normal high 75°F (24°C), low 54°F (12°C) October: normal high 62°F (17°C), low 42°F (6°C) November: normal high 47°F (8°C), low 31°F (-1°C) December: normal high 34°F (1°C), low 20°F (-7°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Rockford?

May has the most wet days (about 13); the year brings about 37 in of precipitation.

January: 10 wet days February: 9 wet days March: 11 wet days April: 12 wet days May: 13 wet days 13 June: 11 wet days July: 9 wet days August: 9 wet days September: 8 wet days 8 October: 10 wet days November: 9 wet days December: 10 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How much does it snow?

Normal snowfall is 37.1 in a year, most of it in January.

January: 10.9 in of snow 10.9 February: 8.5 in of snow March: 4.9 in of snow April: 0.9 in of snow May: 0.0 in of snow 0.0 June: 0.0 in of snow July: 0.0 in of snow August: 0.0 in of snow September: 0.0 in of snow October: 0.2 in of snow November: 2.3 in of snow December: 9.4 in of snow JFMAMJJASOND

How humid is Rockford?

Muggy days peak in July, at about 12 days.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 1 muggy days June: 7 muggy days July: 12 muggy days 12 August: 10 muggy days September: 3 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Greater Rockford Airport, 5.4 mi S of the city center.

How much daylight?

Daylight ranges from about 9.2 hours in December to 15.2 hours in June.

January: 9.5 hours of daylight February: 10.6 hours of daylight March: 11.9 hours of daylight April: 13.4 hours of daylight May: 14.6 hours of daylight June: 15.2 hours of daylight 15.2 July: 14.9 hours of daylight August: 13.8 hours of daylight September: 12.5 hours of daylight October: 11.1 hours of daylight November: 9.8 hours of daylight December: 9.2 hours of daylight 9.2 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Rockford, 1991-2020
MonthHighLowPrecip.Wet daysSnowMuggy daysDaylight
January 29°F15°F 1.6 in10 10.9 in 0 9.5 h
February 33°F18°F 1.6 in9 8.5 in 0 10.6 h
March 47°F28°F 2.4 in11 4.9 in 0 11.9 h
April 60°F39°F 3.8 in12 0.9 in 0 13.4 h
May 71°F50°F 4.2 in13 0.0 in 1 14.6 h
June 81°F60°F 5.2 in11 0.0 in 7 15.2 h
July 84°F64°F 3.8 in9 0.0 in 12 14.9 h
August 82°F62°F 4.2 in9 0.0 in 10 13.8 h
September 75°F54°F 3.6 in8 0.0 in 3 12.5 h
October 62°F42°F 2.6 in10 0.2 in 0 11.1 h
November 47°F31°F 2.3 in9 2.3 in 0 9.8 h
December 34°F20°F 1.9 in10 9.4 in 0 9.2 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Rockford

By our comfort score, the best month is May.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 260427
Feb 310421
Mar 453510
Apr 61972
May 721581
Jun 651084
Jul 59665
Aug 60863
Sep 671452
Oct 591151
Nov 40259
Dec 270523

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Rockford

The last spring frost typically comes around Apr 24, and the first fall frost around Oct 17, leaving 174 frost-free days in a typical year.

Frost and freeze dates for Rockford
Typical date1 year in 10
Last spring frost (32°F)Apr 24after May 8
First fall frost (32°F)Oct 17before Oct 2
Last hard freeze (28°F)Apr 13after Apr 27
First hard freeze (28°F)Oct 28before Oct 14
Frost-free season174 daysunder 154 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Rockford Gtr Rockford Airport (USW00094822), NOAA 1991-2020 freeze probabilities. Frost dates for every city in Illinois.

Hottest and coldest readings, 1991-2020

The highest reading was 105°F (July 7, 2012); the lowest was -31°F (January 31, 2019).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Rockford

Similar climates elsewhere

Where the numbers come from

  • Temperature, rain, snowfall, snow depth, frost dates and humidity and wind by hour: Rockford Gtr Rockford Airport (USW00094822), 5.4 mi S of the city center, 730 ft . NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Greater Rockford Airport (725430-94822), 5.4 mi S of the city center, 725 ft . Hourly observations, 1991-2020.
  • Not available for this location: cloud cover (no station close enough or similar enough in elevation).

Distances from the city center (USGS). Methodology · Report an error