What constitutes ice-on?   It is hard to know what standards were used in the "old days".   Since 1993, we have employed the following standard for determining what is the lake freeze-up date:  when the entire lake is skimmed over by ice (regardless of thickness) and remains so for the rest of the winter.  In this observation we ignore minor areas that may open up because of warm conditions or winds.   This is more or less the standard that is used by observers in other parts of the country.

Ice-off dates are a little more complicated because the melting process tends to be more gradual.    Again we rely on the standard that is suggested by ice observers elsewhere - when the lake is "substantially" ice-free (90% or more) it is considered melted.  Hence there still may be some floating ice or some wind-driven piles of ice along some shorelines.

Detroit Lake Historical Ice Data

Big Floyd Lake Historical Ice Data

Discover PRWD
I am a...

Upcoming Meetings and Events
16 July 2020
July 2020 Board Meeting
20 August 2020
August 2020 Board Meeting
10 September 2020
Public Hearing and September 2020 Meeting
15 October 2020
October 2020 Board Meeting
16 November 2020
North American Lake Management Society Conference

View All

PRWD in the News

PRWD/MN DNR Zebra Mussel impact study

MPR News Story on PRWD Flowering Rush Project

Dan Gunderson, MPR News, visited Lake Sallie with Brent Alcott to discuss the success of the…

MnDNR begins ZM pilot project treatment

View All

Recent Water Levels
Detroit 1334.64 ft
Last Updated: 7/7/2020
Floyd(s) 1354.8 ft
Last Updated: 5/4/2020

Melissa 1328.87 ft
Last Updated: 7/7/2020
Sallie 1329.77 ft
Last Updated: 7/7/2020

Connect with Us