Someone just pointed out this interesting climate extremes tool from the Southern Regional Climate Center. Here is the URL: http://extremes.srcc.lsu.edu/
From there you can choose the product, which is the type of all-time record – for the month, for the day, or for the year. Then you select your variable: record high, record low, etc. And finally the month of interest. So far it only does temperatures and is limited to airport data.
Here is a screen shot of the all-time record highs for April in the Midwest. In the tool, instead of this screen shot, when you mouse over one of the records it gives you more details on the record and dates. It is an interesting tool – I just wish it included the longer NWS Cooperative Observer records.
The statewide average temperature for July was 70.3 degrees in Illinois, which ties the record cool July of 70.3 degrees set back in 2009 and 5 degrees below average.
Below is the plot of July temperatures for Illinois since 1895. The green dots are the actual temperature for each year, while the red and blue shading indicate periods of warmer or cooler temperatures. July 1936 (82.8 degrees) is the warmest July on record, followed closely by July 2012 (81.8 degrees). In the bottom right hand corner, are July 2009 and 2014. So in six years, we have experienced the 2nd warmest and twice the coldest July on record.
As this plot indicates, the observed range in July monthly temperatures in Illinois is 12.5 degrees. On another note, the July 2014 average temperature is based on preliminary data so it is very likely that we will break the tie with 2009 as more data arrives.