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”
Latest News – 6th Coldest Year on Record for Illlinois
The National Climatic Data Center (NCDC) released their numbers for 2014 and Illinois ended up at 49.5 degrees and the 6th coldest year on record for Illinois. Other Midwestern and southern states experienced one of the 10 coldest years for their particular state. Meanwhile, many of the western states experienced one of their warmest years on record. In fact, the two extremes cancelled out leaving the US ranked as the 34th warmest on record.
This result differs from an earlier post where I calculated the 2014 temperature at 49.4 degrees (0.1 degrees colder) based on available data right at the start of the new year. This new calculation moved us from 4th to 6th place in the list. I normally defer to the NCDC numbers and rankings as the final answer on the subject. However, it’s important to keep in mind that their numbers are preliminary as well so the final number and ranking may not be settled for another month or two as more data arrives and is processed.
Cold Start to November in the Midwest
So far, November has been cooler than average across Illinois and the eastern two-thirds of the Midwest (below). The statewide average temperature is about 5 degrees below average.
The NWS forecasts indicate that temperatures are likely to stay below-average for the next two weeks across Illinois and the Midwest. The second and third maps are the latest NWS 6-10 and 8-14 day forecasts.
Ten Coldest March's and What Follows
As previously reported, based on preliminary data this March in Illinois was 34.1 degrees and the 11th coldest March on record. What were the ten coldest March’s on record? I have listed them in the table below. Also I looked to see what happened in April after these chilly March’s. It turns out that half are above average and half are below average – a virtual coin toss.
The columns labeled “Depart” are the departures from the 1981-2010 statewide averages. Probably the biggest turnaround was between March 1960, which was the coldest March on record and 15.5 degrees below average, compared to April 1960 which was 2.2 degrees above average. The statewide temperature records go back to 1895.
| Rank | Year | March | Depart | April | Depart |
| 1 | 1960 | 25.6 | -15.5 | 54.6 | 2.2 |
| 2 | 1906 | 30.3 | -10.8 | 54.5 | 2.1 |
| 3 | 1912 | 30.4 | -10.7 | 52.6 | 0.2 |
| 4 | 1965 | 31.1 | -10.0 | 52.9 | 0.5 |
| 5 | 1984 | 33.0 | -8.1 | 49.8 | -2.6 |
| 6 | 1932 | 33.2 | -7.9 | 52.1 | -0.3 |
| 7 | 1978 | 33.5 | -7.6 | 52.5 | 0.1 |
| 8 | 1989 | 33.5 | -7.6 | 51.1 | -1.3 |
| 9 | 1947 | 33.8 | -7.3 | 51.0 | -1.4 |
| 10 | 1926 | 34.0 | -7.1 | 45.4 | -7.0 |
| 11 | 2013 | 34.1 | -7.0 | ?? | ?? |
BTW, so far this April has been cool. The first 7 days averaged 44.4 degrees statewide, and about 3 degrees below average.