Illinois State Water Survey
Institute of Natural Resource Sustainability
University of Illinois at Urbana-Champaign

Illinois State Climatologist Office

Jim Angel, state climatologist

University of Illinois at Urbana-Champaign

Welcome

This website provides a wide range of climate data, products, and services on Illinois. We have access to more data stored offline. In addition, we do research in Illinois on past climate events, monitor current conditions, and study possible future climate change.

I am available for public talks, media interviews, and research projects. See the About Us page or our brochure (pdf) for more information.

Jim Angel
jimangel@illinois.edu
(217)-333-0729

C-U Observations

Arctic Air Grips Illinois

Cold arctic air caused temperatures and wind chills to plummet in Illinois. Lows on the morning of January 15 were in the minus teens and 20s across much of central and northern Illinois. Only far southern Illinois managed to remain above zero. The coldest reading in the state on January 15 was -28°F at Mt. Carroll. See the minimum temperature map.

An unofficial reading of -37°F was reported at the Rochelle Airport by an automated station. This is far colder than surrounding sites and is probably an error.

New records from around the US can be found at http://www.ncdc.noaa.gov/oa/climate/research/records/index.php

2008 Second Wettest Year on Record in Illinois

The statewide average precipitation for 2008 was 50.7 inches, 11.4 inches above normal and the 2nd wettest year since 1895. Only 1993 was wetter with 51.2 inches.

The statewide average temperature for 2008 was 50.6 degrees, 1.1 degrees below normal and the 18th coolest year since 1895.

December 2008 was both colder and wetter than normal. The statewide average precipitation for December was 4.5 inches, 1.8 inches above normal and the 8th wettest December since 1895. The statewide average temperature for December was 26.3 degrees, 3.5 degrees below normal and the 24th coolest December since 1895.

Chances of a White Christmas in Illinois

What are the historical odds for a white Christmas? The odds range from barely 10 percent in far southern Illinois to over 50% in far northern Illinois. See the map and table.

Cool, Dry November Finishes with First Major Snow of the Season

November in Illinois was both cooler and drier than normal. However, a storm system at the end of the month brought the first significant snowfall of the season across northern and central Illinois. See the November press release.

Let It Snow

The first significant snow of the season fell in the lake-effect snow belt of the Great Lakes on Nov. 17-18. While Illinois missed most of it, northwestern Indiana reported some sizeable amounts including 10.5 inches in Valparaiso. Below are a couple of places to monitor snowfall reports in Illinois and North America. By the way, Nov. 16-22 was winter preparedness week. Check out the new snowfall page.

Late October Freeze Ends Growing Season in Illinois

While far northern Illinois saw freezing temperatures early in the month, the official close to the 2008 growing season at most locations occurred on October 28. Cold Canadian air pushed across the Midwest, producing lows that morning in the mid to upper 20s across Illinois. For most locations, this was about 1 to 2 weeks behind the normal dates of the first fall frost (32 degrees). Normal dates ranges from October 7in northern Illinois, October 14 in central Illinois, and October 21 in southern Illinois.

For October, the statewide precipitation was 2.6 inches, 0.4 inches below normal. The statewide average temperature was 54.2 degrees, only 0.4 degrees below normal. Overall, moderate weather conditions were quite favorable for farmers harvesting corn and soybeans. See the press release.

Gustav and Ike Make 3rd Wettest September

Map of precipitation from first half of September 2008.

Based on preliminary data, the state-wide average precipitation for September was 7.9 inches, making this the third wettest September on record (going back to 1895) for Illinois. The all-time record is 1926 with 9.7 inches while second place goes to 1911 with 9.1 inches. See more on the rains of September.

Chicago (at O'Hare airport) reported 6.64 inches on September 13, setting a new record for the most rain in one calendar day in Chicago's history. The old record was 6.49 inches on August 14, 1987. Chicago climate records date back to 1871.

 

Dry August for Illinois

Based on preliminary numbers, this was the 16th driest August on record for Illinois with 2.3 inches, 1.4 inches below normal. This ends the 8-month streak of above-normal precipitation in Illinois that started in December 2007. The year to date precipitation is 35.1 inches, still 8 inches above normal and the 4th wettest January-August on record. The statewide temperature for August was 71.9 degrees, 1.7 degrees below normal. See the press release for more details.

Wettest January-July on Record for Illinois

This was the wettest January-July on record for Illinois with 32.8 inches, 9.4 inches above normal. State-wide July precipitation was 6.3 inches, 2.5 inches above normal. Every month since December 2007 has had above-normal precipitation. See the press release for more information on the impacts on agriculture.

Heavy Rains and Flooding in Illinois in Spring 2008

Map of Midwestern rainfall in 2008.

Heavy rains in Illinois and across the Midwest have led to considerable problems with flooding, starting in January and continuing through June. While the more severe flooding has occurred in Iowa, several rivers in or along the border of Illinois flooded as well. See more on the flooding and heavy rains of ’08.

 

 

Severe Weather in Illinois in 2008

Small map of tornado reports in the US in 2008.

This year has been much more active in terms of severe weather compared to last year. As of September 1, Illinois has 88 tornado reports compared to only 23 for the entire year of 2007. In addition there have been 408 hail and 663 wind damage reports. See more on the severe weather of 2008.