The Baltic Sea ice season starts when the first ice has formed and ends when the last ice has melted, usually the first ice forms around November and the last remains melt in April or May. But the timeframe can vary from year to year depending on the weather conditions. The table below lists the ice statistics of each year since 1991, including: when the first ice formed, the maximum ice extent, the date of reaching the maximum ice extent and additionally the length of the ice season. The list is based on the Finnish Meterological Institute's data, which is made in collaboration with SMHI.
Yearly statistics of Sea Ice seasons 1991-2025
YearFirst ice formationLength of the seasonMaximum ice extent(km2)Date ofmaximum extent1990/1991 - - 126 000 -1991/1992 - - 74 000 -1992/1993 - - 98 000 -1993/1994 - - 221 000 -1994/1995 - - 76 000 -1995/1996 - - 265 000 -1996/1997 mid November Longer than usual 265 000 February 181997/1998 late October about normal 130 000 March 181998/1999 early November about normal 157 000 February 111999/2000 late November a little bit shorter than usual 95 000 February 242000/2001 late November shorter than usual 129 000 March 262001/2002 early November a little bit shorter than usual 102 000 February 12002/2003 late October longer than usual 233 000 March 52003/2004 late November about normal 153 000 March 112004/2005 mid November shorter than usual 178 000 March 162005/2006 early December about normal 211 000 March 162006/2007 early November shorter than usual 140 000 February 232007/2008 mid November much shorter than usual 49 000 March 242008/2009 mid to late November shorter than usual 110 000 February 202009/2010 early November about normal to slightly longer 244 000 February 172010/2011 mid November longer than usual 309 000 February 252011/2012 early December much shorter than usual 179 000 February 112012/2013 late November about normal 177 000 March 152013/2014 late November shorter than usual 100 000 February 72014/2015 mid November shorter than usual 51 000 January 232015/2016 late November shorter than usual 110 000 January 222016/2017 late November about normal 101 000 February 122017/2018 early November about normal 175 000 March 52018/2019 early December shorter than usual 88 000 January 272019/2020 early December much shorter than usual 37 000 March 52020/2021 mid November shorter than usual 127 000 February 152021/2022 late October longer than usual 93 000 February 42022/2023 early December a little bit shorter 81 000 March 122023/2024 late October longer than usual 135 000 February 122024/2025 early November shorter than usual 85 000 February 202025/2026early Novemberlonger than usual181 000February 20
References
Sea Ice Statistics - Finnish Meteorological Institute (Finnish Meterological Institute's data on sea ice statistics).