So far August has been cooler than normal. And that is likely to continue for a while. Here are the temperature departures for August so far. The statewide average temperature for Illinois is running about 2 degrees below the 1981-2010 normal.
As a cold front swept through Illinois yesterday and today, it has brought cooler and less humid air behind it. And according to the National Weather Service, those cooler temperatures will be around awhile. Over the next 7 days, highs will range from the low 70s in northern Illinois to the mid to upper 70s in central Illinois and the upper 70s and low 80s in southern Illinois. That’s about 6 degrees below normal for this time of year.
The cooler than normal weather is expected to continue with the 6-10 and 8-14 day forecasts showing an increased chance of below-normal temperatures in Illinois (image below, click to enlarge). And these cooler-than-normal conditions could last even longer, according to some models.
The likely impacts of this cooler weather include:
- reduced heat stress in people, especially welcome as school starts around the state,
- lower cooling bills,
- reduced stress on crops, pasture, and lawns, even in areas struggling with dry weather,
- livestock usually benefit from cooler temperatures in late summer with less stress, more weight gain, more milk production, etc.,
- cooler temperatures in late summer can slow down crop development, which is usually more of a concern in northern Illinois than southern Illinois. You can track the impact of the cooler weather on corn using this U2U tool at the Midwestern Regional Climate Center,
- average frost dates in Illinois range from early October in northern Illinois to late October in southern Illinois, in case you are wondering.