Illinois State Water Survey - University of Illinois at Urbana-Champaign

State Climatologist Office for Illinois


Dr. Jim Angel

State Climatologist

Welcome to the State Climatologist Office for Illinois. This website contains a wide range of climate data, maps, and information on Illinois. In addition, we do research in Illinois on past climate events, monitor current conditions, and study possible future climate change (more about us).

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Champaign-Urbana weather observations.

Recently added: high resolution precipitation maps.

Popular Pages


Follow my blog on WordPress at for the latest information on current climate conditions and research.

Illinois At a Glance

Here is a quick glance of current conditions in Illinois from left to right, 1) 30-day, 2) 90-day precipitation departures, 3) 30-day, 4) 90-day temperature departures, and 5) winter snowfall departure from average. Click to enlarge. Here is the link to more maps of current conditions.

Drought Watch

Useful to Usable (U2U) Climate Tools for Agriculture

The Midwestern Regional Climate Center (MRCC) has become the home for the climate tools developed for corn production in the central US. These tools include a corn growing degree day (CGDD) tool for reporting and forecasting CGDDs for current and past growing seasons. The set of tools includes one for examining the effects of El Niño and La Niña, applying nitrogen fertilizer, investing in irrigation, and determining probable fieldwork days. The entire suite of tools can be found on the MRCC U2U page.
Figure. Screenshot of Corn GDD tool, showing increased risk of frost damage before maturity. See actual tool for more details.

Climate Assessment Summary for Illinois

The NOAA Centers for Environmental Information released climate assessments for each state, including the Illinois Climate Summary. The key findings for Illinois are:
  • Average annual temperature has increased by about 1F since the beginning of the 20th century. There has been seasonal variation in this warming, with average spring temperature increasing by about 2F and average summer temperature increasing very little. Under a higher emissions pathway, historically unprecedented warming is projected by the end of the 21st century.
  • Precipitation in spring and summer has generally been above average over the past two decades, affecting agriculture in both positive (adequate soil moisture) and negative (delays in spring planting) ways. Precipitation in winter and spring is projected to increase, which poses a continuing risk of spring planting delays.
  • Severe flooding and drought have occurred periodically in recent years. Future increases in extreme precipitation events and in evaporation rates may increase the intensity of both floods and droughts.
Figure. Plot of 2-inch rainfall events in Illinois over time, showing the increase by 5-year periods since 1900.

Historical Weather Records for Fort Armstrong (1820-1836)

Check out the historical records for Fort Armstrong (1820-1836) on the modern-day Rock Island Arsenal. Fort Armstrong

Climate Events in Illinois Archive

For events from 2012 to present, please see