May 8-14, 2025

Temperatures/Upper Midwest Record Highs

Average temperatures were near normal to the south east over the Ohio Valley, with a steep gradient of above-normal temperatures heading north and west toward Minnesota (Figure 1). In far northwestern Minnesota, temperatures averaged as much as 20°F above normal for the week.

Minimum temperatures averaged above normal in the northwest by up to 15°F (Figure 2). Over most of the rest of the region, minimum temperatures were near normal to slightly below normal. In International Falls, Minnesota, a minimum temperature of 70°F was observed on May 12, which was the all-time warmest minimum temperature recorded there since records began in 1895. In Red Lake Falls, Minnesota a minimum temperature of 66°F was observed for two consecutive days, which tied the record for the warmest stretch of minimum temperatures in May.

Maximum temperatures were well above normal for much of the region (Figure 3). In Minnesota, they averaged 20-25°F above normal for the week. Over Wisconsin and Iowa, they were generally 10-15°F above normal for the week, while over the southern parts of the region, particularly Indiana, Ohio and Kentucky, they were near to slightly above normal. On May 11, International Falls, Minnesota observed a maximum temperature of 86°F, which was 27°F above normal and the all-time warmest May temperature ever recorded there since records began. In International Falls, the maximum temperatures rose to greater than or equal to 90°F for four consecutive days, May 11-14, for the first time in May ever. In Hancock, Michigan on the Keweenaw Peninsula the temperature rose to 89°F on May 11, which was 30°f above normal and the third earliest observation of temperatures 89°f or greater in the calendar year since records began in 1887. In Hancock, maximum temperatures of greater than or equal to 85°F were recorded for three consecutive days in May, which last occurred in 2010 and has only happened four other times since 1887.

Precipitation/Severe Weather/Drought

Precipitation was minimal and focused largely on areas south of I-80, where it was generally 50 percent of normal or less (Figure 4). There was virtually no precipitation across the Upper Midwest. Most of the precipitation fell early in the period with a frontal system, and it was focused over area along and south of the Ohio River and in southern Illinois and southern Missouri.

A severe weather outbreak early in the period brought large hail to parts of Kentucky. Egg sized hail was reported on May 8 via social media in Knox County, Kentucky. Baseball size hail was reported on May 8 in Wayne County, Kentucky. Later in the period, weak tornadoes were reported associated with an outbreak over Indiana and Illinois on May 13.

Drought conditions changed minimally heading through the first two weeks of May. By May 13, drier conditions were actually creeping back into the region, with an 8 percent increase of D0 (abnormally dry) coverage across the region (Figure 5). D1 (moderate drought) also increased in coverage—albeit slightly—over northern Missouri.