January is one of the cooler months of the year in Rockford, with average highs near -3.1°C and lows around -12.2°C (mean -7.6°C). It is one of the drier months, averaging 39 mm of rainfall and 89% relative humidity across the period.
January is one of the cooler months of the year in Rockford. Across 45 years of records, the warmest January in Rockford was 2006 — when the month averaged -0.2°C — while the coldest was 1982 at -15.1°C. Typical January days reach -3.1°C with nights near -12.2°C. The long-term trend is warming, about 0.7°C per decade.
January is one of the drier months in Rockford, averaging 39 mm of rainfall. The wettest January on record was 2005 with 87 mm, while the driest was 1981 at 3 mm.
Relative humidity in Rockford during January averages 89%. The most humid January was 2001 at 97%, and the least humid was 2025 at 75%.
January receives about 1.8 kWh/m²/day of solar energy in Rockford. The sunniest January was 2022 at 2.4 kWh/m²/day, and the cloudiest was 2023 at 1.2.
Average wind speed in Rockford during January is 3.9 m/s. The windiest January was 2014 at 4.7 m/s, while the calmest was 2021 at 3.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -9.5°C | -7.9°C | -6.5°C | -7.6°C | -6.3°C | +3.2°C |
| Avg High | -4.6°C | -3.2°C | -2.2°C | -3.1°C | -2.2°C | +2.4°C |
| Avg Low | -14.4°C | -12.6°C | -10.8°C | -12.2°C | -10.5°C | +3.9°C |
| Avg Rain | 25 mm | 49 mm | 40 mm | 39 mm | 44 mm | +19 mm |
January temperatures in Rockford have risen by about 4.1°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -40.5°C (2019) to a record high of 14.1°C (2008).
Rainfall in January is one of the drier months, averaging 39 mm, with a wettest year of 87 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.5°C per decade while lows rose 0.8°C per decade, narrowing the gap between day and night.
A quieter season to visit Rockford
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Rockford. That said, January — with days averaging -3.1°C and nights around -12.2°C (mean -7.6°C) and moderate rainfall (39 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | -3.1°C | -7.6°C | -12.2°C | 9.5°C | -22.9°C | 14 mm | 75% | 4.5 m/s | 2.2 |
| 2024 | -3.1°C | -6.5°C | -9.9°C | 4.7°C | -28.8°C | 68 mm | 93% | 3.5 m/s | 1.5 |
| 2023 | 0.4°C | -3.0°C | -6.4°C | 7.8°C | -24.0°C | 51 mm | 89% | 3.3 m/s | 1.2 |
| 2022 | -4.7°C | -9.7°C | -14.8°C | 3.5°C | -25.1°C | 14 mm | 85% | 4.2 m/s | 2.4 |
| 2021 | -2.0°C | -6.4°C | -10.8°C | 1.6°C | -20.8°C | 52 mm | 94% | 3.2 m/s | 1.6 |
| 2020 | -0.6°C | -4.6°C | -8.6°C | 6.8°C | -18.2°C | 62 mm | 92% | 3.7 m/s | 1.5 |
| 2019 | -5.0°C | -9.7°C | -14.4°C | 8.1°C | -40.5°C | 56 mm | 91% | 3.8 m/s | 1.7 |
| 2018 | -2.1°C | -6.4°C | -10.6°C | 8.1°C | -24.6°C | 46 mm | 85% | 4.2 m/s | 1.9 |
| 2017 | -0.6°C | -4.3°C | -8.1°C | 9.4°C | -21.0°C | 56 mm | 86% | 3.7 m/s | 1.4 |
| 2016 | -3.1°C | -7.4°C | -11.7°C | 5.6°C | -24.3°C | 19 mm | 91% | 3.6 m/s | 1.8 |
| 2015 | -2.7°C | -7.4°C | -12.2°C | 4.6°C | -25.7°C | 26 mm | 87% | 3.7 m/s | 1.6 |
| 2014 | -7.4°C | -13.5°C | -19.6°C | 1.6°C | -31.1°C | 35 mm | 92% | 4.7 m/s | 2 |
| 2013 | -1.4°C | -6.2°C | -11.1°C | 13.9°C | -22.1°C | 78 mm | 83% | 4.4 m/s | 2 |
| 2012 | 0.2°C | -4.2°C | -8.7°C | 9.6°C | -19.6°C | 31 mm | 87% | 4.1 m/s | 1.9 |
| 2011 | -4.3°C | -8.2°C | -12.2°C | 0.0°C | -26.7°C | 24 mm | 87% | 3.4 m/s | 2 |
| 2010 | -4.8°C | -9.2°C | -13.6°C | 2.4°C | -27.2°C | 23 mm | 94% | 3.5 m/s | 2.1 |
| 2009 | -6.8°C | -12.1°C | -17.4°C | 1.4°C | -33.6°C | 28 mm | 92% | 3.7 m/s | 2.2 |
| 2008 | -2.2°C | -7.1°C | -11.9°C | 14.1°C | -26.8°C | 48 mm | 89% | 4.4 m/s | 1.8 |
| 2007 | -0.4°C | -4.5°C | -8.6°C | 8.4°C | -19.2°C | 40 mm | 87% | 4.2 m/s | 1.8 |
| 2006 🔥 | 3.2°C | -0.2°C | -3.6°C | 9.5°C | -10.1°C | 71 mm | 87% | 4 m/s | 1.6 |
| 2005 🌧️ | -3.6°C | -8.1°C | -12.6°C | 6.0°C | -25.2°C | 87 mm | 90% | 3.5 m/s | 1.6 |
| 2004 | -4.6°C | -8.8°C | -13.1°C | 9.1°C | -25.7°C | 18 mm | 84% | 4.2 m/s | 1.7 |
| 2003 | -4.0°C | -8.1°C | -12.3°C | 9.1°C | -21.8°C | 10 mm | 76% | 4.1 m/s | 2 |
| 2002 | 1.6°C | -2.2°C | -6.0°C | 10.8°C | -15.8°C | 25 mm | 87% | 3.9 m/s | 1.8 |
| 2001 | -3.2°C | -7.7°C | -12.2°C | 1.0°C | -21.8°C | 36 mm | 97% | 3.3 m/s | 2 |
| 2000 | -2.0°C | -6.2°C | -10.3°C | 10.0°C | -20.2°C | 31 mm | 85% | 4 m/s | 1.7 |
| 1999 | -4.8°C | -9.2°C | -13.5°C | 4.6°C | -30.5°C | 81 mm | 93% | 4 m/s | 1.9 |
| 1998 | -0.1°C | -4.1°C | -8.2°C | 9.3°C | -23.8°C | 59 mm | 91% | 3.5 m/s | 1.9 |
| 1997 | -4.6°C | -9.1°C | -13.6°C | 13.0°C | -29.0°C | 43 mm | 88% | 4.4 m/s | 1.8 |
| 1996 | -3.3°C | -8.5°C | -13.6°C | 12.6°C | -34.9°C | 46 mm | 88% | 4.4 m/s | 1.6 |
| 1995 | -3.5°C | -7.8°C | -12.0°C | 3.7°C | -20.4°C | 53 mm | 91% | 3.7 m/s | 1.8 |
| 1994 | -7.6°C | -12.1°C | -16.5°C | 1.3°C | -34.0°C | 38 mm | 91% | 3.9 m/s | 1.8 |
| 1993 | -3.2°C | -8.4°C | -13.6°C | 2.9°C | -24.2°C | 58 mm | 93% | 3.6 m/s | 1.8 |
| 1992 | -0.9°C | -4.9°C | -9.0°C | 4.1°C | -25.2°C | 37 mm | 90% | 3.9 m/s | 1.5 |
| 1991 | -6.1°C | -12.0°C | -18.0°C | 0.5°C | -29.9°C | 28 mm | 96% | 3.9 m/s | 1.9 |
| 1990 | 1.7°C | -3.2°C | -8.2°C | 7.3°C | -15.2°C | 48 mm | 86% | 4.5 m/s | 1.8 |
| 1989 | 0.6°C | -4.2°C | -9.0°C | 12.5°C | -24.3°C | 16 mm | 88% | 4.5 m/s | 1.6 |
| 1988 | -7.3°C | -12.5°C | -17.8°C | 7.0°C | -35.2°C | 61 mm | 96% | 4.1 m/s | 1.6 |
| 1987 | -1.9°C | -5.7°C | -9.5°C | 4.2°C | -23.3°C | 22 mm | 88% | 3.6 m/s | 1.9 |
| 1986 | -4.6°C | -9.4°C | -14.2°C | 4.1°C | -30.8°C | 21 mm | 94% | 4.1 m/s | 1.7 |
| 1985 | -7.5°C | -13.2°C | -18.9°C | -0.2°C | -37.3°C | 25 mm | 93% | 4.4 m/s | 2.2 |
| 1984 | -6.5°C | -11.6°C | -16.8°C | 0.1°C | -36.1°C | 16 mm | 96% | 3.4 m/s | 1.8 |
| 1983 | -1.1°C | -5.1°C | -9.1°C | 3.1°C | -16.4°C | 12 mm | 88% | 3.9 m/s | — |
| 1982 ❄️ | -9.1°C | -15.1°C | -21.0°C | 0.6°C | -39.9°C | 46 mm | 94% | 4.6 m/s | — |
| 1981 | -3.8°C | -8.5°C | -13.2°C | 7.5°C | -27.2°C | 3 mm | 86% | 3.5 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around -3.1°C with lows near -12.2°C (mean -7.6°C), based on 45 years of NASA POWER data.
January averages 39 mm of rainfall in Rockford, one of the drier months. The wettest on record was 87 mm in 2005.
The hottest January reached 14.1°C in 2008. The coldest dipped to -40.5°C in 2019.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 4.1°C. Daytime highs moved from -5.6°C to -2.5°C and overnight lows from -15.8°C to -10.8°C over the same span.
January is one of the cooler months of the year in Rockford and one of the drier months, so plan for around -3.1°C daytime highs and -12.2°C at night.
Yes — January is the coldest month of the year in Rockford, averaging -7.6°C.
For January in Rockford, pack warm layers and a jacket for chilly mornings, with typical highs of -3.1°C and lows of -12.2°C.
Relative humidity in January averages 89% — quite humid.
Average wind speed in January is 3.9 m/s. The windiest January on record averaged 4.7 m/s (2014).
The wettest January on record was 2005 with 87 mm. On average, January sees 39 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Rockford behaves each January, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for January specifically, along with year-by-year records and how the month has changed over the decades.
