Rockford climate
Rockford (Illinois, United States) has a hot-summer humid continental climate (Köppen Dfa). The average temperature over the year is 9 °C48 °F, and about 967 mm38 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Rockford climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | −228 | −1112 | −720 | 391.5 | 30 |
| Feb | 032 | −1014 | −523 | 431.7 | 27 |
| Mar | 745 | −326 | 235 | 602.4 | 24 |
| Apr | 1559 | 236 | 947 | 933.7 | 10 |
| May | 2170 | 948 | 1559 | 1084.3 | 1 |
| Jun | 2679 | 1559 | 2169 | 1295.1 | 0 |
| Jul | 2883 | 1864 | 2373 | 1044.1 | 0 |
| Aug | 2781 | 1762 | 2272 | 1074.2 | 0 |
| Sep | 2475 | 1253 | 1864 | 933.7 | 0 |
| Oct | 1660 | 540 | 1050 | 803.2 | 6 |
| Nov | 846 | −229 | 338 | 562.2 | 20 |
| Dec | 033 | −818 | −425 | 542.1 | 29 |
| Year | 2883 | −1112 | 948 | 96738 | 147 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 88% | 67% | 1.8 | 9:25 |
| Feb | 85% | 64% | 2.8 | 10:30 |
| Mar | 80% | 63% | 3.7 | 11:49 |
| Apr | 76% | 62% | 4.7 | 13:19 |
| May | 77% | 63% | 5.5 | 14:34 |
| Jun | 77% | 56% | 6.2 | 15:15 |
| Jul | 76% | 48% | 6.3 | 14:58 |
| Aug | 75% | 49% | 5.5 | 13:53 |
| Sep | 76% | 47% | 4.4 | 12:25 |
| Oct | 77% | 59% | 2.9 | 10:59 |
| Nov | 81% | 64% | 1.9 | 9:43 |
| Dec | 88% | 70% | 1.4 | 9:06 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Rockford is like
The warmest month is July, with an average high of 28 °C83 °F and a low of 18 °C64 °F. The coldest is January, when highs average −2 °C28 °F and lows −11 °C12 °F. Seasons are strongly marked: the warmest month is on average 29.8 °C53.7 °F warmer than the coldest.
Annual precipitation is moderate at about 967 mm38 in. The wettest three-month stretch is May–July, which brings 35% of the annual total. The wettest month is June (129 mm5.1 in), the driest is January (39 mm1.5 in).
Relative humidity ranges from 75% in August to 88% in December. The clearest skies (lowest average cloud amount, 47%) are typical of September. Average wind speed near the ground ranges from 8 km/h (5 mph) in August to 14 km/h (9 mph) in February. Daylight lasts from about 9.1 hours in December to 15.3 hours in June.
A lasting snow cover is typical in December–March. In those months the average snow depth in the reanalysis exceeds 10 cm. It is deepest in January, at about 16 cm.
Best time to visit Rockford
Based on these averages, the most comfortable months for sightseeing and outdoor activities are May and July–September. Average highs then reach 21 °C70 °F to 28 °C83 °F. Precipitation is 93 mm3.7 in to 108 mm4.3 in per month.
The most challenging month is January, which is cold, with average highs of −2 °C28 °F.
Comfort score: months are ranked by how close they come to an ideal. That means an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Rockford
- Winter (December–February) — highs −228 to 0 °C33 °F, lows −1112 to −8 °C18 °F, about 45 mm1.8 in of precipitation a month. Pack a winter coat, hat, gloves and warm, non-slip boots and shoes with good grip, as frost is common.
- Spring (March–May) — highs 745 to 21 °C70 °F, lows −326 to 9 °C48 °F, about 87 mm3.4 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an extra layer for the cooler mornings and evenings.
- Summer (June–August) — highs 2679 to 28 °C83 °F, lows 1559 to 18 °C64 °F, about 113 mm4.5 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Autumn (September–November) — highs 846 to 24 °C75 °F, lows −229 to 12 °C53 °F, about 76 mm3.0 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an extra layer for the cooler mornings and evenings.
How Rockford compares
The nearest larger place is Aurora, about 86 km to the southeast. Compared with it, Rockford is on average 0.7 °C1.3 °F cooler. It receives a similar amount of precipitation. The difference is largest in January (1.4 °C2.5 °F cooler).
World Climates covers 222 places in the United States. By annual mean temperature, Rockford is the 212th warmest of them. By annual precipitation, it is the 113th wettest. See all of them on the United States climate page.
Some places in other countries have a very similar pattern of temperature and rainfall. The closest matches are Windsor (Canada, Dfa), Brampton (Canada, Dfa) and Brantford (Canada, Dfa).
Nearby places
- Climate in Elgin 72 km · 10 °C49 °F · 983 mm39 in
- Climate in Aurora 86 km · 10 °C49 °F · 983 mm39 in
- Climate in Madison 93 km · 8 °C47 °F · 970 mm38 in
- Climate in Joliet 118 km · 10 °C51 °F · 985 mm39 in
- Climate in Chicago 128 km · 10 °C50 °F · 982 mm39 in
- Climate in Milwaukee 129 km · 9 °C48 °F · 945 mm37 in
- Climate in Davenport 148 km · 10 °C51 °F · 924 mm36 in
- Climate in Peoria 180 km · 11 °C52 °F · 983 mm39 in
Frequently asked questions
What is the warmest month in Rockford?
July is the warmest month in Rockford. Its average high is 28 °C (83 °F) and its average low is 18 °C (64 °F).
What is the coldest month in Rockford?
January is the coldest month. Its average high is -2 °C (28 °F) and its average low is -11 °C (12 °F).
When does it rain the most in Rockford?
June is the wettest month with about 129 mm (5.1 in) of precipitation. January is the driest with about 39 mm (1.5 in).
What is the best time to visit Rockford?
Judging by long-term averages, the most comfortable months are May and July–September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station. So they can differ from airport records. The gaps are largest on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.