- A Detroit heat wave is likely to bring at least five days in the mid- to upper 90s, with heat index readings rising above 100.
- High overnight temperatures and the early timing of the heat wave could add to the risk for Detroiters, who are urged to take measures to protect themselves and check in on relatives and neighbors.
- The city of Detroit has opened cooling centers at recreation centers. Residents are also encouraged to visit branch libraries to beat the heat.
- The heat is also likely to contribute to high ozone levels, which can cause respiratory problems and increase the frequency of asthma attacks.
The coming Detroit heat wave could be the worst the area has seen in 20 years, with the potential for five days in the mid to upper 90s. The National Weather Service issued an excessive heat warning for Metro Detroit for Monday afternoon through Friday evening. However, high temperatures may last into the weekend as a punishing ‘heat dome’ settles over the eastern U.S.
The city of Detroit is making recreation centers and libraries available for cooling this week.
The extreme heat could be especially dangerous in the city of Detroit, where heat index values may rise above 100 F, according to the NWS. Relatively high overnight temperatures in Detroit pose a special risk for those who lack air conditioning or are vulnerable to heat illness, including children, those 65 or older and people with chronic health conditions.
The NWS advises residents to drink plenty of fluids, stay out of the sun and in an air-conditioned space if possible, and check in on relatives and neighbors.
Sunshine and heat are also driving ozone formation, which poses a risk for those with asthma, which will be worse during the hottest part of the day.
The climate crisis, caused by the burning of fossil fuels, is expected to increase the frequency, duration and severity of heat waves in the Midwest.
How long will the Detroit heat wave last?
Temperatures in the upper 90s could last from Monday through Friday, Steven Freitag, a meteorologist with the NWS, told Planet Detroit. And above average temperatures are likely to continue in southeast Michigan for the next 6 to 10 days, according to the National Oceanic and Atmospheric Administration’s Climate Prediction Center.
Freitag said Detroit may see overnight lows in the upper 70s. Experts warn that high overnight temperatures can be especially dangerous during a heat wave because the body doesn’t have a chance to cool down, raising the risk of heat illness or death. Heat waves that arrive earlier in the year also pose a special risk because bodies haven’t had a chance to acclimate to hotter temperatures. These events are associated with higher mortality than heat waves that occur later in the summer.
The urban heat island effect, or the tendency of impervious surfaces like roads, buildings and other infrastructure to trap heat and warm the surrounding area, also makes Detroit more vulnerable during these periods of hot weather. A 2023 analysis from Climate Central found that 86% of neighborhoods in Detroit and its inner-ring suburbs experience an increase in temperature of up to 8 F or more from the heat island effect. This heat island effect can be more pronounced at night, adding to the risk of extreme heat.
The heat in southeast Michigan forms the western edge of the heat dome settling over the eastern U.S., creating heat index readings of 100 F or above for an area stretching from the Gulf of Mexico to Nova Scotia.
Heat domes occur when a high-pressure system moves into an area, pressing warm air toward the ground. This high-pressure bubble can divert storm systems, creating a static weather pattern with mostly clear skies that amplify the heat.
Freitag said there was a greater chance of showers and thunderstorms on the western edge of the heat dome, which could cool things down. However, storms could also lead to power outages in Detroit, a danger during a heat wave when residents depend on fans and air conditioning.
Air quality concerns come with the heat
Michigan regulators issued an air quality advisory for ozone in Detroit on Sunday and Monday. When cars, factories and other sources emit volatile organic compounds (VOCs) and nitrogen oxides (NOX) in the presence of heat and sunlight, chemical reactions between the pollutants create ozone, which is more likely to reach dangerous levels on hot and sunny days. Ozone pollution can cause respiratory problems and increase the frequency of asthma attacks.
The Michigan Department of Environment, Great Lakes, and Energy’s Air Quality Division expects ozone levels to be in the Air Quality Index’s “unhealthy for sensitive groups” range in Detroit on Monday. Alec Kownacki, a meteorologist with EGLE’s Air Quality Division, told Planet Detroit that it was the “perfect setup” for ozone pollution from Monday through Wednesday.
Ozone poses less of a problem indoors, as long as windows and doors are closed, because it reacts with building materials, resulting in lower ozone levels. Kownacki recommended those with asthma stay inside during the hottest part of the day.
EGLE also cautioned residents to avoid activities that contribute to ozone formation, such as refueling vehicles and using gas-powered lawn equipment or charcoal lighter fluid. Kownacki advised people not to overexert themselves during the heat and drink lots of water. Experts say that spending even just a few hours in air conditioning during a heat wave can help a person’s body stay cool when they go back into the heat.