Remember September? It was cooler than normal, the sun blocked by California and Oregon’s wildfire smoke. Maximum temperatures averaged 3.8 degrees below the century’s 71.4 monthly average high from the 12th through the end of the month.

Recall that warm was the norm the first 10 days. Temperatures topped 80 degrees three of four days starting the 7th. Half of those days saw highs above 75 degrees. That changed abruptly on the 12th, when the high was 59 degrees. Only two days rose above 72 degrees the rest of the month, while on 13 days it stayed in the 60s and twice, on the 12th and 26...