Happy New Year! In honor of the day when folks change out their calendars, the featured chart presents one of the many calendar plots that you can generate on this website. The featured chart presents the number of daily issued Special Weather Statements (abbreviated SPS for fun legacy reasons) that contain a polygon by NWS Davenport. This product can be issued any time of the year and can sometimes cover quick hitting winter events, but it most often used to cover slightly sub-severe convective storms. The IEM Automated Data Plotter tool has a number of calendar plot generation apps, including one for SPC/WPC outlooks, daily observation summaries, and daily NWS warning counts.

The first day of 2026 started off a bit chilly with afternoon temperatures below freezing for nearly the entire state. Both Burlington (SE Iowa) and Sioux City (NW Iowa) had afternoon high temperatures of 28°F and that is the subject of today's feature chart. The top panel presents the difference in afternoon high temperature between the two sites by week of the year. The darker green colors indicate higher frequency and a simple weekly average is fit to the data with the plotted line. The bottom panel partitions the temperature difference by Sioux City average wind speed over the afternoon period. The top panel shows the difference between the two sites is the strongest during the cold half of the year, but the magnitude is only a few degrees.