Minnesota's Fishing Opener weather is typified by partly cloudy to cloudy skies, morning temperatures in the low 40's, and afternoon temperatures climbing to near 70. Three out of four years are free of measurable precipitation. A trace of snow has been reported in northern Minnesota on at least five of the last 64 fishing openers. On at least four occasions, some lakes were still frozen for the opener. Generally there is enough wind to be felt on the face, maybe enough to 'fly' a flag. Weather on Minnesota fishing opener dates is highly variable. 64 years of fishing opener weather data are summarized here to offer a glimpse of what is 'typical' and what is 'extreme.'
Opening day temperatures have started as low as 24 degrees at International Falls (1996,2004), with freezing temperatures possible even in Minneapolis (31 degrees in 1979). On the warm side, St. Cloud saw 92 degrees in 1987, Minneapolis reported 91 in 1987, and International Falls reached 88 in 1977. The average early morning temperature varies from the high 30's in the northeast to the high 40's along the southern border. The average afternoon temperature generally ranges from the mid 60's along the northern border, to the low 70's in the extreme south. Along the shore of Lake Superior, highs are held in the mid 50's.
Three quarters of past opening days have been free of measurable precipitation. Two thirds of the fishing openers have been free of any precipitation, measurable or not. On those days with measurable rain, the amounts averaged close to a half-inch in the south and a quarter inch in the north. No amounts over one inch were recorded at International Falls, while Minneapolis experienced 1.15 in 1962 and 1.64 in 1965. St. Cloud saw 1.03 inches in 2008. Snowfall has generally has been limited to traces. Traces of snow were officially recorded in 1963, 1993, and 2009 at International Falls, and in 1968 at St. Cloud. A tenth (.1) of an inch fell at International Falls in 2000.
Statewide, less than one year in five offers totally clear skies. The average amount of cloudiness lies near that fuzzy boundary between 'partly cloudy' and 'cloudy', but over half of the dates were classified as cloudy.
Average daily wind speeds generally range between 8 and 15 miles per hour. This range can is described as 'wind felt on face ...' to '... wind extends light flag'. The predominant wind direction is split fairly evenly between blowing from the northwest, south, and east.
Fog has been reported on the fishing opener, occurring about one year in ten in the south, about one year in six in the north. By early to mid May, Minnesota is entering its thunderstorm season. The possibility of thunderstorms is greatest in the south (about one in seven), less in the north (about one in eleven). The weather should be monitored carefully if the skies appear threatening.
For May 12, 2012 at St. Cloud, the sun will rise at 5:49 a.m.; sunset will come at 8:38 p.m. For International Falls, sunrise/sunset is 5:36 a.m. and 8:45 p.m. respectively. For Minneapolis, sunrise will be 5:47 a.m. and sunset at 8:33 p.m. Add one minute for each 10 miles west of a given location (at the same latitude) to get a rough estimate of sunrise and sunset times. Sunrise/sunset information can be obtained for any community using a Web site offered by the US Naval Observatory.
Fishing opener 2011 was cloudy and cold over the central and south, with light rain and drizzle. Temperatures were more seasonable over the north with some sunshine. Breezy conditions existed all day statewide.
And finally, yes there have been years with ice covered lakes for the opener. On opening day in 1950, lakes were still frozen as far south as Detroit Lakes and Osakis. Four other years with frozen lakes, primarily in the north, were 1966, 1979, 1996, 2008 and 2009. Just a couple lakes in the far northeastern tip of Minnesota still had ice on them for the '09 opener.
This season, the ice left the lakes at a record pace across most of Minnesota. The ice left lakes in southern Minnesota from two to three weeks ahead of long term averages, and from three weeks to nearly a month early across the central and north. The 2012 Governor's Fishing Opener is on Lake Waconia. The average date of ice out for Lake Waconia is April 10. This season the lake became ice free on March 18.
More information about fishing in Minnesota can be found at the Department of Natural Resources.
A history of past fishing openers back to 1948 can be found at the Minnesota Historical Society.
Good Luck!