IRON MOUNTAIN — A blast of summer heat lies ahead this week, but a return to more seasonable temperatures is likely for the rest of May, forecasters say.
As for the start of summer, the National Weather Service is neutral on both temperature and precipitation trends in the Upper Peninsula through the end of July, while AccuWeather pegs the region for a moderate risk of severe weather.
The storm threat for Wisconsin and some other areas of the Midwest is higher, according to AccuWeather meteorologist Brian Lada. “While the wet pattern will fuel severe weather, it will help to limit the potential for heat waves across the regions,” he added.
Temperatures at Iron Mountain-Kingsford are expected to climb into the 80s on Thursday and Friday, then retreat slightly over the weekend. Showers and thunderstorms are possible through Thursday, including a 50% chance Tuesday.
AccuWeather’s May forecast suggests the danger of a hard frost has passed, though typically that date at Iron Mountain-Kingsford is May 26. In 2021, the last spring day with a temperature below 32 degrees was May 29, while in 2020 it was May 13 , NWS records show.
The soil temperature has climbed about 10 degrees since the end of April, according to greencastonline.com. The 24-hour average on Sunday morning was 52 degrees, about equal to the 10-year trend. At the start of the month, the soil temperature locally was 5 degrees below normal.
The far eastern UP is abnormally dry but otherwise the US Drought Monitor shows in areas of concern in most of Michigan and northern Wisconsin.
La Nina conditions are expected to continue into summer and maybe into fall, Climate Prediction Center forecasters say. La Nina, the flip side of El Nino, is the periodic cooling of the central Pacific Ocean that affects weather patterns around the globe.
The expected pattern this summer raises concerns for early heat and an increase in drought conditions across the Plains and Southwest, Weather Channel meteorologist Linda Lam said. There is extreme drought in most of New Mexico as well as western Texas and Oklahoma.
The Iron Mountain-Kingsford Wastewater Treatment Plant measured 3.34 inches of water-equivalent precipitation in April, which was more than a half-inch above normal. Snowfall totaled 4 inches for the month, but none of it lingered.
The highest temperature last month at Iron Mountain-Kingsford was 73 degrees on April 25, while an 18-degree reading on April 28 was the coldest on record since the early 1900s.
Temperatures averaged 37.4 degrees for the month, about 3 degrees below normal. It may have seemed cooler, as daytime highs averaged just 45.1 degrees — about 7 degrees under the norm.
Overnight lows were actually a bit warmer than normal, averaging 29.7 degrees in April compared with the typical 29 degrees. Overall, it was the 19th-coldest April at Iron Mountain-Kingsford.