Sioux Falls should continue a weather phenomenon that dates back to August of 2015. A warm streak will extend for 20 consecutive months.

Unfortunately the Kingswood Rummage Sale is on the short end of the trend as it will be virtually impossible to have a cooler than normal April average temperature. Even though the last six days will be lower than typical temperatures.

Certainty comes in the calculations as Brandon Spinner of KDLT Weather explains the formula for average monthly temperature.

“Add every high temperature and every low temperature of the month together. Then divide it by (2 times the number of days so far in the month) Example 2,500 degrees / (2 x 25 days) = average temp of 50 degrees.”

Coming into April 26, 2017 the current equation is 2,544 degrees / (2 x 25 days) = average temp of 50.4 degrees. To be normal in April, the math looks like this: 2792 degrees / (2 x 30 days) = average temp of 46.5 degrees.

With five days left in the month, there’s only 248 degrees to utilize before topping normal. Forecasted temperature values will be around 406 degrees. Projected average high temperature equation (the math nerds are loving this) is 2950 degrees / (2 x 30 days) = average temp of 49.2 degrees.

Will the trend continue for 21 consecutive months? Initially early May looks to continue our current cooling trend to start the month, but there’s 31 days until we know for sure.