Heatwave Expected This Weekend

Our first real, long lasting heatwave is set to move in over weekend and it is bringing some heat that some of us haven’t seen in nearly three years! So far we have seen a handful of 90-degree days across the area, but nothing really back to back. Sioux Falls has only recorded two 90-degree days coming on June 9th and July 5th. The only two towns in the KDLT coverage area that have recorded back to back 90-degree days are Winner (July 4 & 5) and Mobridge (June 8 & 9). That is all about to change.

This heatwave is partially due to the subtropical jet, which will make its way into the northern United States, allowing for all that heat to build in from the south. By Saturday afternoon the jet will have pushed towards northern Nebraska, bringing the humidity and heat with it. Temperatures will climb into the upper 80s and low 90s across the area, accompanied by some very high dew points, meaning humidity will be very high.

By Sunday, the jet will move into southern North Dakota allowing for more of that heat to move into the area, bringing a possibility for the 100s in southern South Dakota, including Pierre and Sioux Falls. This heat dome will stay through Monday and Tuesday as well before dipping a little further south to wrap up the week. However, the above average heat is expected to last through next weekend.


This heat will bring us some of our warmest temperatures in over two years! The last time Sioux Falls hit 96° or warmer was September 11th of 2013! The last time we eclipsed the 100-degree mark in Sioux Falls was August 30th, 2013, so needless to say it has been a while.

Over the last two and a half years we have seen a lack of heat across the area. The summer of 2012 delivered nearly 50 days of 90-degrees or warmer in Sioux Falls, but over the last three years we have only combined to see 17. In Pierre, that number in 2012 was 58 with only 43 90-degree days since.

Combined with this heat will be plenty of humidity. Dewpoints will climb into the upper 60s and low 70s across the area over the weekend. This combined with the hot temperatures will lead to “feels like” temperatures (A.K.A Heat Index) to climb over 100 even if the air temp stays below the century mark. Humidity levels will dip slightly into early parts of next week, however they will still be oppressive.

Our longest heatwave of the year is expected to last at least a week. Almost every one of the next seven days is expected to be above our average temperature for that date.

Please remember to drink plenty of water and stay hydrated. Also make sure to take as many breaks as necessary if you plan to be outdoors in this heat. It doesn’t take long to get a heat illness in this type of heat.

-Brandon Spinner
Chief Meteorologist