Temperature
Based on the official data, the statewide average temperature was 44.5 degrees, 8.1 degrees below normal. It was the second coldest April on record, only beaten by 43.1 degrees set in April 1907. Our statewide records go back to 1895. Normal refers to a specific benchmark, the 1981-2010 average. See the longer explanation here.
Here are the temperature departures from normal look like across the Midwest. Areas in green are 1 to 9 degrees below normal, while areas in icy blue are 9 or more degrees below normal. The lowest temperature reported in Illinois for April was -1 at both Avon and Lincoln on April 2. At the other extreme, we did reach into the 80s at times during the month. The warmest reading was 86 degrees at Kaskaskia on April 13.
Precipitation Continue reading “Second Coldest April on Record in Illinois”
5th Warmest November, 2nd Warmest Fall in Illinois
Temperature
This was the 5th warmest November on record for Illinois, based on preliminary data. The statewide average temperature was 47.4 degrees, and 4.9 degrees above normal. Here are the top ten warmest Novembers in Illinois since 1895:
- 2001 with 49.9°F
- 1931 with 49.1°F
- 1909 with 48.8°F
- 1999 with 48.4°F
- 2016 with 47.4°F
- 2009 with 47.2°F
- 1902 with 46.9°F
- 1990 with 46.8°F
- 2015 with 46.6°F
- 1913 with 46.4°F
It was also the 2nd warmest fall on record for Illinois. The statewide average temperature for fall was 59.4 degrees, 5 degrees above normal. Only the fall of 1931 was warmer at 59.8 degrees. The climatological fall months are September, October, and November.
Precipitation
Continue reading “5th Warmest November, 2nd Warmest Fall in Illinois”
Average Date of First Snow in Illinois
I have noticed that the average date of the first snow is a popular search term on the blog, so here is the reposting of the median dates of the first measurable snowfall of the season in Illinois. This map is based on 1971-2000 data. While it is not based on the current 1981-2010 averages, the map is still relevant for the purpose of getting an idea of the dates. Measurable snowfall means at least a tenth of an inch.
Median Date:
In the northern third of Illinois, the first snowfall occurred around Thanksgiving. The dates switch from November to December once you reach central Illinois (just north of a line between Quincy and Champaign). By the time you reach Carbondale, the date can be as late as December 20. From this you can see that we are by no means behind schedule this year.
Early Date:
Widespread Heavy Rain Expected this Week
The rain has finally moved into Illinois this morning. According to the National Weather Service, widespread heavy rain is expected to continue in Illinois over the next 3 days. Here is the forecast map for Tuesday morning showing a large storm moving across the central US. Rain is likely from the Gulf of Mexico all the way up to the western Great Lakes. Snow is likely in the Plains states (areas in blue). However, we will likely be too warm in Illinois to see snowfall.
