Showers and a few thunderstorms as reinforcing cool air arrives; How rare are 40s this late in June?

SHOWERS THIS EVENING
We reinforce the cool air as a front dips south this evening. There are a few showers and a couple of thunderstorms northwest and will reach central Indiana before diminishing completely by 11 - 12 am.
SEPTEMBER-LIKE
Fast forward 3 months and this is the weather we get. Temperatures were at September 24th levels Monday afternoon, the normal high is 85-degrees.  Even cooler tonight!
NEARING RECORD LOWS
The work week opened rather chilly Monday with portions of western Indiana starting in the upper 40s.  We will beat many of the early Monday low temps on Tuesday.  The rare 40s in late June included 48-degrees in Rockville.
It will really take on a Fall-like feel in summer with a NEAR RECORD low early Tuesday morning in Indianapolis.  The record of 48-degrees was set in 1926!
We have not dipped to or below 50° this late in a June since 2004!  A scan of weather records shows only 7 times has a June 26th through the 30th gone to 50 or cooler over 146 years!