Links to reports:

 

The average was around 5 degrees below normal and there were many days that were 10 degrees below normal.  The 29th appears to be exceptionally cool with Pierre nearly 20 degrees below normal. 

 

The reason for this is pretty simple.  What is known as a trough was over the eastern US and has been pretty consistent for quite some time (with the exception of this past week).  There was also a ridge over the western US which brought more heat to the Pacific coast.  It got so strong at one point that Seattle saw an all time record heat.  This set up kept our upper level flow from the northwest and brought cooler temperatures in from southwest Canada.  Here's a look at the 500mb (upper levels) from the evening of July 17th. 

 

 

Those little blue lines show the direction the wind is coming from.  The trough is the area where lines make a dip.  In this map its from the Lake Huron, down the Illinois/Indiana border and down the Mississippi River.  The ridge is that big area over the southwestern US that looks like two circles, one of which is over the Arizona/Utah border. 

 

I think I explained this, but let me know if you have questions either in the comments or at dfabert@ksfy.com. 

 

For precipitation, it was sort of all over the place, which it is normal to see that for July because thunderstorms can be very scattered.  Some places were as low as two inches below normal and some were above normal. 

 

If you want to check out the monthly data for your area, you can check it out pretty simply. 

 

1.)  Go to your National Weather Service for your area:  Sioux Falls, Aberdeen, or Pierre.

 

2.)  Click on the climate tab and you should be on the observed weather graphic tab.

 

3.)  The Preliminary Monthly Climate Data CF6 is the product you want, select your city, then your month of choice and hit go!