January weather in Janesville, WI
The average temperature in Janesville in January is 19.9°F (11.6°F–28.3°F). Average precipitation: 1.63 inches. Average snowfall is 10.8 inches.
January is a winter month in Janesville, and is cooler than the annual average of 47.8°F. Daily temperatures swing about 16.7°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 9h 12m. For travel, January is cold.
Avg High
28.3°F
Avg Low
11.6°F
Precipitation
1.63 in
Snow
10.8 in
January records in Janesville
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| January 1 | 51.1°F (2007) | -14.1°F (2018) | 0.50 in (2019) |
| January 2 | 48.0°F (2005) | -15.0°F (1991) | 1.20 in (2005) |
| January 3 | 55.9°F (2000) | -15.0°F (2014) | 0.60 in (1990) |
| January 4 | 54.0°F (1998) | -15.0°F (1988) | 0.64 in (1993) |
| January 5 | 59.0°F (1997) | -23.1°F (1999) | 1.80 in (2004) |
| January 6 | 55.9°F (2008) | -23.1°F (1999) | 0.55 in (2005) |
| January 7 | 60.1°F (2008) | -23.1°F (1999) | 0.52 in (1998) |
| January 8 | 50.0°F (2019) | -23.1°F (1999) | 0.50 in (2019) |
| January 9 | 57.9°F (2026) | -18.9°F (1988) | 0.53 in (1998) |
| January 10 | 54.0°F (2002) | -18.0°F (1988) | 0.37 in (2009) |
| January 11 | 52.0°F (2012) | -9.0°F (1999) | 0.68 in (2013) |
| January 12 | 54.0°F (2012) | -9.0°F (1997) | 0.22 in (2018) |
| January 13 | 54.0°F (2006) | -11.9°F (2016) | 1.01 in (2005) |
| January 14 | 53.1°F (2026) | -15.0°F (1994) | 0.73 in (1995) |
| January 15 | 52.0°F (1990) | -22.0°F (1994) | 0.32 in (2007) |
| January 16 | 52.0°F (1990) | -24.0°F (2009) | 0.24 in (1997) |
| January 17 | 51.1°F (1990) | -24.0°F (2009) | 0.58 in (2017) |
| January 18 | 55.0°F (1996) | -26.0°F (1994) | 0.64 in (2020) |
| January 19 | 57.0°F (1996) | -27.9°F (1994) | 1.08 in (1988) |
| January 20 | 51.1°F (2006) | -26.0°F (1994) | 0.43 in (1995) |
| January 21 | 46.0°F (2018) | -26.0°F (1994) | 0.32 in (2012) |
| January 22 | 53.1°F (2017) | -13.0°F (2025) | 0.70 in (2005) |
| January 23 | 50.0°F (2002) | -16.1°F (2026) | 0.99 in (2018) |
| January 24 | 45.0°F (2002) | -16.1°F (2026) | 0.48 in (1999) |
| January 25 | 41.0°F (1993) | -14.1°F (1991) | 0.40 in (2020) |
| January 26 | 50.0°F (2002) | -18.9°F (2019) | 0.29 in (2021) |
| January 27 | 52.0°F (2002) | -20.0°F (2019) | 0.90 in (2004) |
| January 28 | 57.9°F (2002) | -15.0°F (2014) | 0.42 in (2019) |
| January 29 | 54.0°F (1988) | -15.0°F (2014) | 1.35 in (2006) |
| January 30 | 57.9°F (2013) | -26.0°F (2019) | 0.92 in (2001) |
| January 31 | 59.0°F (1989) | -29.9°F (2019) | 0.43 in (2013) |