The short story: we had frost last night. The solidified dew on my car that I felt at about 6:30 confirms it, along with the frost-burned squash leaves in the garden. Luckily, most of the garden survived with no apparent damage, thanks to our diligent covering.
We were not under a freeze warning last night, or even a frost advisory. The frost advisory was one county to the north. But I knew better.
The temperature on our pessimistic thermometer read 28 or so. Brrr! The official low temperature at Embarrass, the cold weather capital of Minnesota, was 27. They made news headlines for it, with the qualification that "this is very unusual weather for here!"
Hmmmm? I believe that in at least three out of the four last summers here we have had a killing frost in August, if not July. At any rate, the garden has been pretty much toast by mid September. So, unusual?
I think this is a very local thing. We're in a bit of a low area. Heidi, how did your garden fare?