ALPENA, Mich. — Alpena tied its hottest summer on record. The average of daily high and low temperatures throughout June, July and August was more than six degrees above the long-term normal!
Meteorologist Patrick Bak from the National Weather Service explains what led to the persistent heat this past season. “We found a good portion of the country was under a big ridge of high pressure for a lot of the summer. We were on the edge of that, so it just kept us in a warmer pattern than we normally would see.”
Looking at long term averages, the jet stream usually travels through northern Michigan during the summer. Sometimes it dips south, giving us cool spells and sometimes the jet stream rides north, giving us heat waves.
This year, the jet stream was displaced north of Lake Superior, resulting in a more persistent hot pattern in much of Michigan over the summer.
Four out of the top five hottest summers on record in Alpena have happened after 2010. Looking at trends from the 1970s until 2019, the average summer temperature is increasing by more than two degrees.