December weather in Fontana-on-Geneva Lake, WI
The average temperature in Fontana-on-Geneva Lake in December is 27.1°F (19.6°F–34.5°F). Average precipitation: 1.83 inches.
December is a winter month in Fontana-on-Geneva Lake, and is cooler than the annual average of 47.6°F. Daily temperatures swing about 14.9°F between overnight low and afternoon high. Daylight averages about 8h 53m. For travel, December is cold.
Avg High
34.5°F
Avg Low
19.6°F
Precipitation
1.83 in
Daylight
8h 53m
December records in Fontana-on-Geneva Lake
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 51.1°F (2017) | 3.0°F (2025) | 0.92 in (2015) |
| December 2 | 55.0°F (2012) | 6.1°F (2025) | 0.64 in (2018) |
| December 3 | 57.0°F (2012) | 14.0°F (2025) | 0.42 in (2011) |
| December 4 | 66.0°F (2012) | -0.9°F (2025) | 0.46 in (2011) |
| December 5 | 60.1°F (2017) | 0.0°F (2025) | 0.28 in (2016) |
| December 6 | 53.1°F (2012) | 14.0°F (2013) | 0.24 in (2021) |
| December 7 | 44.1°F (2012) | 8.1°F (2013) | 0.18 in (2025) |
| December 8 | 48.9°F (2023) | -6.0°F (2025) | 0.10 in (2014) |
| December 9 | 55.0°F (2023) | 7.0°F (2025) | 0.46 in (2023) |
| December 10 | 51.1°F (2024) | 0.0°F (2013) | 0.45 in (2022) |
| December 11 | 55.0°F (2015) | 9.0°F (2013) | 0.88 in (2021) |
| December 12 | 46.0°F (2015) | 1.9°F (2013) | 0.50 in (2020) |
| December 13 | 57.9°F (2015) | 3.9°F (2025) | 0.20 in (2015) |
| December 14 | 60.1°F (2015) | -5.1°F (2025) | 1.50 in (2015) |
| December 15 | 57.0°F (2015) | -5.1°F (2025) | 1.00 in (2022) |
| December 16 | 64.9°F (2021) | 0.0°F (2016) | 0.47 in (2012) |
| December 17 | 50.0°F (2015) | 0.0°F (2016) | 0.95 in (2016) |
| December 18 | 42.1°F (2023) | 3.9°F (2016) | 0.20 in (2016) |
| December 19 | 45.0°F (2025) | -5.1°F (2016) | 0.14 in (2025) |
| December 20 | 46.0°F (2017) | -4.0°F (2016) | 0.70 in (2012) |
| December 21 | 48.0°F (2015) | 6.1°F (2024) | 0.98 in (2012) |
| December 22 | 46.9°F (2019) | 6.1°F (2024) | 0.44 in (2015) |
| December 23 | 51.1°F (2015) | -8.0°F (2022) | 0.41 in (2023) |
| December 24 | 55.9°F (2015) | -2.9°F (2022) | 0.68 in (2015) |
| December 25 | 55.9°F (2015) | -2.0°F (2013) | 0.08 in (2017) |
| December 26 | 55.9°F (2023) | -7.1°F (2017) | 0.28 in (2023) |
| December 27 | 46.9°F (2014) | -4.0°F (2017) | 0.46 in (2021) |
| December 28 | 50.0°F (2024) | -2.0°F (2017) | 0.41 in (2018) |
| December 29 | 50.0°F (2024) | 7.0°F (2017) | 0.98 in (2015) |
| December 30 | 55.0°F (2022) | -2.9°F (2013) | 0.64 in (2020) |
| December 31 | 39.9°F (2024) | 0.0°F (2013) | 0.29 in (2011) |