Above-normal autumn temperatures continued into November across much of the lower 48 states, but history suggests that pattern may give way to more frequent periods of below-normal temperatures this winter.

In most of Iowa, the period from Nov. 1-18 averaged from 9 to 13 degrees warmer than normal, before some cooler weather arrived later in the month.

Fall precipitation was running well below normal in parts of south-central and southeastern Iowa into late November. October precipitation averaged 0.54 inch below normal, and November precipitation was light during a large part...