The preliminary statewide average November temperature was 42.3 degrees, 0.1 degree above the 1991–2020 average and tied for the 46th warmest on record going back to 1895. The preliminary statewide average total November precipitation was 0.74 inches, 2.34 inches below the 1991–2020 average and the eighth driest on record statewide.
Data are provisional and may change slightly over time. The official November precipitation total may be affected by the rainfall on the evening of November 30. Depending on if this precipitation is counted as on November 30 or December 1, which varies by the station, the official November total may be higher than the preliminary.
Mild November with a Chilly End
November can be a challenging month for those yearning for summer to come back. However, as daily average temperature departures in Dixon show, the past month brought mostly mild temperatures that felt more like mid-fall than early winter (Figure 1). Several days in the second and third weeks of the month were 5 to 10 degrees warmer than normal. Black Friday brought a big temperature change on the back of a strong cold front. The last week of the month saw temperatures that that were 5 to 15 degrees below normal, including several nighttime low temperatures in the single digits.
November temperatures ranged from the high 40s in northern Illinois to the high 50s in southern Illinois, around 1 degree above normal (Figure 2). Several places saw high temperatures into the 80s in early to mid-November, including 84 degrees in Lawrenceville and 82 degrees in Cahokia. Meanwhile, the last week of the month brought some extremely low temperatures, including 3 degrees in Minonk and 4 degrees in Aurora. The coldest point in the state last month was Elizabeth at 36.6 degrees, and the warmest point was Lawrenceville at 49.1 degrees.
Where is that November Rain?
Most of Illinois got a good shot of rain in late October and saw its first snow around Halloween. However, the state moved into a much drier weather pattern that persisted for most of November. Month-total precipitation ranged from nearly 3 inches in northeast Illinois to less than half an inch in parts of south-central Illinois. Northern Illinois was 1 to 2 inches drier than normal, and southern Illinois was 3 to 4 inches drier than normal (Figure 3). Last month was a top five driest November in several places in the state, including the second driest on record in Fairfield (Table 1).
Table 1. November total precipitation and historical ranking at several locations in Illinois.
|November Total Precipitation (inches)
Overall, the preliminary statewide average total November precipitation was 0.74 inches, 2.34 inches below the 1991–2020 average and the eighth driest on record statewide.
Fall in Illinois
Climatological fall includes September, October, and November, and–for my money–it is the best weather season Illinois has to offer. This past season’s average temperatures ranged from the low 50s in northern Illinois to the low 60s in southern Illinois, around 1 degree above normal (Figure 4).
Fall season total precipitation ranged from over 15 inches in northern Illinois to less than 4 inches in parts of southwest Illinois. The season was near 1 to 2 inches wetter than normal in northern and parts of central Illinois and was 4 to 8 inches drier than normal in southern Illinois. Last season was the driest fall on record in Chester, with a record back to the 1890s, and it was the fourth driest fall on record in Quincy and the driest since 1956. Speaking of Quincy, Gem City is well on its way to a top five driest calendar year of its 120+ year record. Drought has consequently been a constant in much of western Illinois this year, causing agriculture and water resource impacts.
Overall, the preliminary statewide average fall temperature was 55.7 degrees, 1.1 degrees above the 1991–2020 average and tied for the 27th warmest on record going back to 1895. The preliminary statewide average total fall precipitation was 6.87 inches, 2.82 inches below the 1991–2020 average and the 30th driest on record statewide.
Snowfall before December is typical for central and northern Illinois, and, unlike post-March snowfall, is not universally despised. Most of northern Illinois saw its first measurable snowfall around Halloween, while central Illinois had to wait until the weekend after Thanksgiving to see the white stuff accumulate. Fall season snow totals ranged from a tenth to a quarter of an inch along the Interstate 72 corridor up to 5 inches between Peoria and Monmouth (Figure 6). Most of the state outside of the Peoria to Monmouth corridor is a little less than 1 inch beyond on season-to-date snowfall, thanks to milder October and November temperatures. It’s important to note that neither an early start to snowfall nor unusually high snow totals before December forewarn snowfall between December and February.
Welcome to winter! December brings in the coldest, snowiest season of the year. However, this winter also comes with a moderate-to-strong El Niño, which often moderates winter temperatures and limits snowfall. The December outlooks lead into that pattern, with the highest chances of above normal temperatures for the final month of the year (Figure 7a). Not much changes in the winter season (December–February) outlooks, with the highest chances of both warmer than normal and drier than normal conditions across the state (Figure 7b).