05/29/2026
❄️ Now that we're safely done with winter, how did this one stack up to prior years? The Midwest Regional Climate Center (MRCC) at Purdue created a metric in 2015 to compare the severity of winter seasons called the Accumulated Winter Season Severity Index (AWSSI). Here's a two-sentence summary of the AWSSI from its original paper:
"The character of a winter can be defined by many of its features, including temperature averages and extremes, snowfall totals, snow depth, and the duration between onset and cessation of winter-weather conditions. The accumulated winter season severity index incorporates these elements into one site-specific value that defines the severity of a particular winter, especially when examined in the context of climatological values for that site."
Here's a look at stations across Michigan where they've calculated the AWSSI using the descriptions of the winter season from "Extreme" to "Mild." Points shown are for the 2025-2026 winter, but the AWSSI has been calculated for previous years, with many stations having decades of data included. The true power of the site is within the individual station graphs. Marquette, MI is shown here as an example. Check out the interactive map and graphics at this link: https://mrcc.purdue.edu/research/awssi
