Monthly Science: Well Pit Temperature

With more data, those February lows really stand out:

Well Pit Air Temperature - 2014-10 to 2015-05-31
Well Pit Air Temperature – 2014-10 to 2015-05-31

The February daily record shows more detail:

Well Pit - 2015-02-25
Well Pit – 2015-02-25

I’d say the air temperature in the pit got close to freezing, but surely a stream of cold air falling through the vent hole would wash over the logger and depress the results.

Should I get powerfully motivated, I’ll strap the logger onto one of the pipes, wrap insulation around it, and have it take data from early December through late March in one session; lifting the concrete slab requires enough effort that I’m not going to do it, ah, lightly during the snow season.