Illinois State Water Survey Illinois State Climatologist

New Climate Prediction Center Outlooks

On February 20, the NWS Climate Prediction Center released their new outlooks for March and beyond. Below are the maps for March, spring (March to May), and summer (June to August).
The overall theme for Illinois is an increased chance of above-average temperatures through August. We have an increased chance of above-average precipitation in the March-May period, followed by equal chances in the June-August period. If it pans out, above-average precipitation for this spring should help with low water levels on both the Great Lakes and Mississippi River as well as alleviate drought concerns in northern Illinois.
If you are wondering when was the last time we had a spring that was both warmer and wetter than average, you do not have to look very far. The springs of 2004, 2006, 2009, 2010, and 2011 all qualified as having both above average on precipitation and temperature. In fact, our spring temperatures in Illinois have been at or above average in all but 2 years since 1998 (last figure).

The Climate Prediction Center outlook for March and March-May. NOAA.
The Climate Prediction Center outlook for March and March-May. NOAA.

Climate Prediction Center outlook for summer (June-August).
Climate Prediction Center temperature outlook for summer (June-August).

Climate Prediction Center precipitation outlook for summer (June-August).
Climate Prediction Center precipitation outlook for summer (June-August).

Spring Temperatures in Illinois since 1895. Source: http://www.southernclimate.org/products/trends.php
Spring Temperatures in Illinois since 1895. The green dots are the spring temperatures each year. The shaded curve represents a 5-year running average with extended periods of cool temperatures shaded in blue and extended periods of warm temperatures shaded in red. Source: http://www.southernclimate.org/products/trends.php