Press release on disaster declaration
On January 26, 2011, the USDA granted the Illinois Department of Agriculture’s request for federal disaster assistance for southern Illinois farmers who suffered crop losses caused by drought in 2010. The 16 counties are for the most part south of Interstate 64. The full press release can be seen here.
Rainfall amounts in parts of southern Illinois were much below normal from May all the way through October. However, the pattern and sequence of rain events varied from month to month and place to place. Therefore it’s hard to make a general statement about all the counties in the declared region. For example, Cairo IL received 28.6″ of rain from April to September (over 6 inches above normal) while Fairfield received only 17.1 inches (over 6 inches below normal).
Two contributing factors to crop losses are the regions shallow soils that hold less water and temperatures that were about 3 degrees above normal.
Here are two maps that show the percent of normal precipitation for the period of April-June 2010 and July-September 2010. As a rule of thumb, any 3-month rainfall totals less than 70% of normal is cause for concern. Click maps to enlarge.