If you’re looking for a hot time this holiday weekend, just step outside Saturday. Temperatures will be in the 90s, and the heat index could climb to 100, weather forecasters say. The expected high Saturday is 94.

The steamy conditions begin today when temperatures will climb into the mid-80s with a heat index around 90.

The Michigan Department of Natural Resources and Environment said the conditions could lead to high ground-level ozone and has declared today an ozone action day, asking people to avoid refueling automobiles and using lawn equipment, among other things.

Saturday could also bring an isolated shower or thunderstorm early in the day, then scattered showers and thunderstorms after 3 p.m.

Sunday and Monday will bring more pleasant temperatures with highs in the mid- to upper-80s Sunday and in the mid-80s Monday.

And it doesn’t look like it will rain on anyone’s July 4 parade. Conditions will be mostly sunny Sunday and Monday, the National Weather Service says.

For updated conditions and forecasts anytime, check AnnArbor.com's weather page.