The soil temperature near the base of the bird box, under a few inches of chipped leaf mulch, shows the expected trend for the growing season, but there’s a weird bump in mid-October:
The NWS temperature summary confirms the anomaly, with the DEP column giving the departure from the historic average:
DY MAX MIN AVG DEP ================== 1 65 58 62 5 2 72 58 65 9 3 73 49 61 5 4 65 51 58 2 5 62 40 51 -4 6 70 38 54 -1 7 76 52 64 10 8 74 52 63 9 9 70 44 57 4 10 63 37 50 -3 11 56 44 50 -3 12 63 35 49 -3 13 63 37 50 -2 14 78 59 69 17 15 79 69 74 23 16 72 53 63 12 17 73 52 63 13 18 68 50 59 9 19 56 33 45 -5 20 61 30 46 -4 21 57 48 53 4 22 53 50 52 3 23 52 48 50 2 24 59 41 50 2 25 66 34 50 2 26 58 43 51 3 27 64 38 51 4 28 73 38 56 9 29 68 42 55 8
The precipitation record shows over an inch of rain in those four days, so that weather probably blew in from the south.
The Smell of Molten Projects in the Morning 