Steamy Tropical-like Summer Weather in MN


Starting this weekend until mid-next week, Minnesota is expected to experience temperatures in the 90s with over 70% humidity, resembling a typical steamy tropical climate. This is the first instance of temperatures above 90 degrees this season.

According to CNN Weather, “an expansive and exceptionally strong heat dome builds Sunday over the East and expands to reach the Midwest and Great Lakes over the following days, ushering in the regions’ first significant heat wave of the year. Heat domes trap air in place and bake it with abundant sunshine for days on end, making each day hotter than the last”.

A heat dome, as described by the National Weather Service’s Alex Lamers to NPR, acts like a lid on a pot, intensifying the heat trapped beneath it much like a lid speeds up the melting of cheese in a pan.

If you’ve made grilled cheese in a pan and you put a lid on there, it melts the cheese faster because the lid helps trap the heat and makes it a little bit warmer. It’s a similar concept here: You get a big high-pressure system in the upper parts of the atmosphere and it allows that heat to build underneath over multiple days.

– Alex Lamers, National Weather Service (source: NPR)

Heat domes are driven by expansive high-pressure systems in the atmosphere that may cover vast areas, often spanning several states. These systems create stagnant conditions linked to ridges in the jet stream, exacerbating extreme heat and drought. The jet stream’s northern position currently prevents moisture from reaching the Southwest, prolonging the heatwave and intensifying its effects.

This phenomenon is currently causing temperatures in the Western U.S. to soar to 20-30 degrees above average for early June, with cities like Phoenix and Las Vegas expected to reach 112 degrees Fahrenheit, accompanied by minimal nighttime cooling. Health officials warn of the dangers of prolonged exposure to extreme heat.

Climatologist and meteorologist Mark Seeley, told MPR News that the Climate Prediction Center predicts June statewide to be much wetter than usual, breaking a trend from the last three years.

According to MNPR News, “The rain is also expected to come with heat. This week, seven Minnesota counties reported afternoon high temperatures around 90 degrees Fahrenheit. That high temp is expected to become more common going into next week.”

This recent BBC article covers how Americans in the West are figuring out ways to keep themselves cool and protected from the current heat dome.