Another powerful heat dome is showing early signs of targeting Michigan, especially Southern Lower Michigan, during the last week of July. According to multiple medium-range weather models, including the ECMWF and the GFS, we may be heading into a hotter-than-average period just before the end of the month.
For the third day in a row, both the European model (ECMWF) and the NOAA Global Forecast System (GFS) continue to highlight the development of a warm upper-air pattern. This signals the formation of what meteorologists call a “hot dome”—a region where high pressure traps warm air aloft and drives up surface temperatures.
Starting around July 23, the ECMWF shows a shift in the wind flow at 15,000 feet, marking the beginning of this hot phase. While the intensity may not match the brutal heat wave of mid-June, when temperatures peaked at 99°F (37°C) in parts of Michigan, this round of late-July heat could still bring several days of 90°F+ (32°C+) highs.
If the pattern continues to evolve as predicted, Southern Lower Michigan could find itself under the influence of this dome for three to five days. Daily highs are currently projected to reach between 92°F and 95°F (33°C to 35°C)—well above the seasonal average.
This time of year—the final days of July and the start of August—is historically one of Michigan’s warmest stretches, and current forecasts suggest that 2025 will be no exception. The intensifying sun, combined with this upper-level ridge, could set the stage for classic deep-summer weather across much of the state.
Stay tuned as forecast confidence builds in the coming days, and keep an eye on how this evolving heat dome might impact your local weather across Michigan.
