29. Advisories and Warnings were in place for cold temperatures last night.
Most of the region was under a Frost Advisory for temperatures forecast to fall near freezing, while a section of northern Wisconsin was issued a Freeze Warning for temperatures below 32 F.
This map (to the right), from USWX.com, shows where the Advisories and Warnings were located.
The warnings were warrented, in fact, they could have been expanded a little, since sub-freezing temperatures were reported in the Frost-warned areas.
None of the seeds in my garden have germinated yet, I'm planting late on purpose, so while I recorded 30.7 degrees for a low temperature, no damage occurred at my location. Many locations dropped lower than what I recorded.
Overnight lows from MesoWest.
I went through the reports on MesoWest and compiled the overnight low temperatures into a spreadsheet (to the left).
The coldest was 22 degrees in central Bayfield Co., away from Lake Superior. Along the shoreline in northern Bayfield Co., 39 degrees was reported. Quite a large temperature difference.