Historically Speaking, When Do We Get Our First Hard Freeze?
Fall is definitely here, and the leaves are changing fast. Another part of the season is that first hard freeze, when temperatures fall below 28 degrees overnight. While we've been enjoying a relatively warm fall so far, when does our area traditionally see this for the first time of the season?
It's no secret that it varies quite a bit depending on where you are. Lake Superior plays a massive role in so much of the region's weather, and first freeze dates are no different. The Twin Cities office of the National Weather Service shared a graphic on social media this week depicting these average dates (seen below).
Areas away from Lake Superior, on the Iron Range and in Northwestern Wisconsin, usually see their first freeze between September 21 and September 30. Yep, that means we're historically in a window of time where it isn't abnormal for parts of our area. As far as the immediate Duluth-Superior area, October 1-October 10 is our "normal" window. The North Shore and Bayfield Peninsula see the greatest influence from Lake Superior, getting the latest average first freeze dates. Average first freeze in those places is between October 11 and October 20. While that is the latest in our region, that isn't the latest average dates in the state.
The latest average dates for Minnesota and Wisconsin is the last part of October, between the 21st and 31st. This happens in the Mississippi River Valley in Southeastern Minnesota/West Central Wisconsin as well as along the Lake Michigan shoreline in Eastern Wisconsin. There is actually an even later average in far Southeastern Wisconsin. The Milwaukee area and places south see a first average freeze in the first week of November.
Will we stick to our averages this year? Some areas might not. The National Weather Service's Climate Prediction Center is seeing a high likelihood of warmer than average temperatures for Minnesota and Wisconsin for the next two weeks. As we get into October, however, the outlook favors average to slightly below average temperatures possible as we get into the middle of October.