Temperatures have remained below normal across southern Wisconsin since about April 20th. However for the month of April, the average temperature at Milwaukee and Madison remains about 1-2 degrees above normal due to the unseasonable warmth experienced earlier this month.
A change in the upper level steering winds and more widespread sunshine is going to result in a warming trend these final days of April, 2015, continuing into the first days of May. With the warm weather will come plans for spring planting. However before rushing to the local nursery, check out the below graphics which depict a climatology of average spring dates of when to expect the last freezing (32 degrees) and 28 degree temperatures across Wisconsin and the western Great Lakes. The period of record for this climatology is from 1980 to 2010 and is provided by the Midwest Regional Climate Center.
The below image depicts the median Spring date of the last 32 degree temperature across Wisconsin and the region. For southern Wisconsin, the average date is anywhere from mid-April to mid-May, with the area around Reedsburg and Baraboo typically experiencing the latest freezing temperature.
The below graphic depicts the median date of the last 28 degree temperature across Wisconsin and the region. Across southern Wisconsin this typically occurs in mid to late April, with the area around Baraboo toward Spring Green lingering into the first week of May.
The below graphics depict the dates of the earliest and latest last 32 degree and 28 degree temperatures across Wisconsin and the region:
Here is a look at how temperatures will be warming in the next week at both Milwaukee and Madison:
Madison is expected to rise to above normal daytime temperatures early this coming week, while Lake Michigan keeps daytime temperatures in Milwaukee much cooler until later in the week when winds become more south to southeasterly.
Enjoy the warmer temperatures this week!
Kavinsky/Herzog
National Weather Service - Milwaukee/Sullivan