View recent freezing and thawing statistics for three Madison-area lakes — Mendota, Monona, and Wingra — as well as ice averages and extremes.
Note: The freezing date is the first date that the majority of the lake surface is estimated to be frozen. No reliable information on ice thickness is available. See how ice-in, ice-out dates are determined for Madison lakes
This Year (2023-2024)
| Mendota | Monona | Wingra | |
| Date lake froze | January 15 | January 15 | December 13, December 19, January 5 |
| Date lake opened | February 28 | February 28 | December 17, December 24, February 28 |
| Days of ice cover | 44 | 44 | 63 |
Last Year (2022-2023)
| Mendota | Monona | Wingra | |
| Date lake froze | December 25 | December 19 | November 21, December 18 |
| Date lake opened | April 2 | March 20 | November 28, March 20 |
| Days of ice cover | 98 | 91 | 99 |
2021-2022
| Mendota | Monona | Wingra | |
|---|---|---|---|
| Date lake froze | January 7 | January 3 | December 7, December 23 |
| Date lake opened | April 2 | March 26 | December 16, March 25 |
| Days of ice cover | 85 | 82 | 101 |
Median Dates and Duration of Ice Cover
| Mendota | Monona | Wingra | |
|---|---|---|---|
| Median freeze date | December 20 | December 15 | November 29 |
| Median opening date | April 4 | March 30 | March 25 |
| Median days of ice cover | 102 | 103 | 113 |
Record Dates for Lakes to Freeze
| Mendota | Monona | Wingra | |
|---|---|---|---|
| Earliest freeze date | November 23, 1880 | November 22, 1880 | November 2, 1913 |
| Second-earliest freeze date | November 25, 1857 | November 23, 1857 | November 5, 1991 |
| Latest freeze date | January 30, 1932 | January 30, 1932 | December 30, 2015 |
| Second-latest freeze date | January 20, 2007 | January 18, 2007 | December 29, 1877 |
Record Dates for Lakes to Open
| Mendota | Monona | Wingra | |
|---|---|---|---|
| Earliest opening date | February 27, 1998 | February 26, 2002 | February 26, 1998 |
| Second-earliest opening date | February 28, 2024 | February 27, 1998 | February 27, 2017 |
| Latest opening date | May 6, 1857 | May 4, 1857 | April 29, 1881 |
| Second-latest opening date | May 3, 1881 | May 1, 1881 | April 19, 1975 |
Records for Duration of Ice Cover
(Number of days and season)
| Mendota | Monona | Wingra | |
|---|---|---|---|
| Shortest duration | 21 (2001-02) | 44 (2023-24) | 63 (2023-24) |
| Second-shortest duration | 44 (2023-24) | 49 (1997-98) | 69 (2015-16) |
| Longest duration | 161 (1880-81) | 160 (1880-81) | 164 (1880-81) |
| Second-longest duration | 151 (1856-57) | 151 (1856-57) | 145 (1887-88) |