Dangerous, extreme heat conditions in Northern Minnesota

The National Weather Service issued an extreme heat warning lasting until 7 p.m. Tuesday, July 14.

The hot temperatures from the weekend continued into the week, with Tuesday forecast to stay in the 90s.

Josh Sandstrom, a meteorologist for the National Weather Service in Duluth, said in the midst of this heat wave, temperatures are expected to go no lower than the mid-60s to mid-70s in the overnight hours.

“It’s a concern that there isn’t going to be much recovery from the heat during the overnight hours,” Sandstrom said. “That plays a factor as well, especially when you have multiple days of these hot and humid conditions. It just doesn’t give people time to recover for that.”

While it is expected to cool off slightly on Wednesday, temperatures will stay high enough that additional heat advisories may be put in place Wednesday and Thursday, Sandstrom said. The heat combined with low relative humidity and wind is exacerbating fire weather conditions at a rare time of year, contributing to spread of wildfires in the Boundary Waters Canoe Area Wilderness. And the lack of rainfall is deepening drought conditions.

Three main factors go into determining heat warnings. The first is the heat index, which is what the temperature feels like to the human body. Another is the wet bulb globe temperature, which measures the heat stress in direct sunlight. Last is the heat risk, which looks at the potential risk for heat related impacts.

The heat risk for Northern Minnesota through Tuesday is classified as major. Pockets of the area are classified as extreme — the highest heat risk rating.

As the heat continues, Sandstrom recommended doing a few things to mitigate the extreme heat effects.

"Drinking plenty of fluids, stay in air conditioned rooms if you have air conditioning, or find a place where there's cooling shelters or an area to get out of the sun. And then also checking up on relatives and neighbors who are also in that more vulnerable population with regards to heat itself."

Sandstrom warned that given the extreme level of heat, there is a significant risk for heat-related illnesses in the area, specifically during the afternoon and early evening hours when peak heat is reached.