Breakup and freezeup of the Red River at Winnipeg, Manitoba Canada in the 19th century and some climatic implications

Abstract

Breakup and freezeup dates for the Red River at Winnipeg, Manitoba, Canada, were compiled from archival sources for the period from 1815 to the beginning of published data in 1908. Median 19th C dates of freezeup and break-up were 12 and 10 days earlier and later respectively than during the 20th C, and the average ‘ice-in’ season was nearly three weeks longer. Correlation of breakup and freezeup dates with spring and fall temperatures suggests that both seasons were about 25 °C cooler in the 19th C than in the 20th. The change appears to have occurred rapidly at the end of the 19th C.