| Month | Average (°F) | Record (°F) | Average (inches) | |||
|---|---|---|---|---|---|---|
| High ☀️ | Low 🌙 | High ☀️ | Low 🌙 | Precipitation 💧 | Snow ❄️ | |
| January | 28.1 | 11.5 | 60 | -30 | 1.7 | 11.9 |
| February | 32.4 | 14.4 | 74 | -31 | 1.6 | 9.9 |
| March | 44.6 | 25.1 | 83 | -13 | 2.1 | 4.3 |
| April | 57.9 | 35.8 | 91 | 5 | 3.6 | 1.3 |
| May | 70.0 | 47.7 | 96 | 17 | 4.1 | 0.0 |
| June | 79.9 | 57.7 | 101 | 32 | 4.9 | 0.0 |
| July | 83.3 | 61.4 | 103 | 41 | 4.2 | 0.0 |
| August | 81.8 | 59.4 | 102 | 40 | 4.3 | 0.0 |
| September | 75.1 | 50.8 | 101 | 27 | 3.7 | 0.0 |
| October | 61.7 | 39.3 | 89 | 11 | 3.0 | 0.2 |
| November | 46.3 | 28.3 | 78 | -17 | 2.4 | 2.0 |
| December | 33.5 | 18.1 | 67 | -25 | 1.9 | 9.9 |
| Entire year | 58.0 | 37.4 | 103 | -31 | 37.2 | 40.0 |
|
More Janesville Weather Records
1893–2024
|
||
|---|---|---|
| Highest daily low | 79 °F | August 27, 1973 |
| Lowest daily high | -15 °F | January 19, 1994 |
| Greatest daily range (Difference of high and low) |
66 °F | April 7, 1893 |
| Greatest difference in daily high over two conscutive days |
49 °F | Jan 19–20, 1996 |
| Most daily precipitation | 4.5 inches | September 13, 1961 |
| Most monthly precipitation | 17.4 inches | August 2007 |
| Most yearly precipitation | 49.9 inches | 2019 |
| Most yearly days with precipitation | 161 | 2019 |
| Earliest snow in season | October 18 | 1972 |
| Latest snow in season | May 11 | 1966 |
| Most daily snow | 12.5 inches | December 7, 1994 |
| Most monthly snow | 33.7 inches | December 2008 |
| Most yearly snow | 93.1 inches | 2008 |
| Most snow in a winter | 86.7 inches | 2007–2008 |
| Greatest snow accumulation | 36.0 inches | January 24, 1979 |
| Earliest freeze | September 16 | 1916 |
| Earliest day ≥ 80 °F | March 16 | 2012 |
| Earliest day ≥ 90 °F | April 22 | 1980 |
| Earliest day ≥ 100 °F | June 19 | 1953 |
| Latest freeze | May 27 | 1992 |
| Latest day ≥ 80 °F | October 31 | 1950 |
| Latest day ≥ 90 °F | September 30 | 1971 |
| Latest day ≥ 100 °F | September 2 | 1953 |
| Most days in a year < 0 °F | 40 | 1963 |
| Most days in a year < 32 °F | 165 | 1996 |
| Most days in a year ≥ 80 °F | 111 | 1953 |
| Most days in a year ≥ 90 °F | 45 | 2012 |
| Most days in a year ≥ 100 °F | 7 | 1988 |
|
Janesville Weather Streaks
Most consecutive days...
|
||
|---|---|---|
| With precipitation | 10 days | Apr 7–16, 2013 |
| Without precipitation | 36 days | May 23 – Jun 27, 1988 |
| With snow | 9 days | Feb 4–12, 2018 |
| High temperature at or below freezing |
49 days | Jan 2 – Feb 19, 1979 |
| High temperature ≥ 80 °F | 76 days | Jun 15 – Aug 29, 1955 |
| High temperature ≥ 90 °F | 15 days | Jul 9–23, 1983 |
| High temperature ≥ 100 °F | 3 days | Jul 5–7, 2012 |