We've been advertising a big cool down for early next week with highs only in the sixties. Strong north winds will even make it fell a tad cooler.
We've seen this before, it happened in 2009 when Sioux Falls had highs ranging from seventy-one to seventy-seven July 16 through 18, which averaged ten degrees below the climate average of 84. We even recorded a record low of 50 July 18 that year.
Here's the upper air pattern from that time. It shows a strong low pressure system just north of Lake Superior, allowing cold Canadian air in.
Forecast models for next week have been showing a very similar pattern.
The rest of the month that year remained cool with an average high of seventy-three, the highs ranged from seventy to 85. Unfortunately, the rain stayed away with Sioux Falls only recording three-quarters of an inch for the last two weeks of the month. We'll see if we follow those patterns this year.