Hot temperatures and poor air quality are on tap Friday across Colorado’s Front Range.

The National Weather Service in Boulder said to expect high temperatures to reach 91 degrees in Denver on Friday under mostly sunny skies with patchy smoke moving in after 8 a.m. It should dissipate by about 9 p.m.

The Colorado Department of Public Health and Environment issued an Ozone Action Day Alert through at least 4 p.m. on Friday due to wildfire smoke from Mesa County.

“Ozone may reach levels that are unhealthy for sensitive groups in the northern Front Range region including Denver, Fort Collins and Greeley,” the CDPHE said.

State health officials said the particulate matter (PM2.5) in the air was at elevated levels and could cause respiratory problems for unusually sensitive people.

“Unusually sensitive people should consider reducing prolonged or heavy exertion,” health officials said.

An Air Quality Health Advisory was issued for Mesa County, including Grand Junction and Gateway due to the wildfire smoke through 9 a.m. Friday.

Wildfires in western Colorado have consumed more than 42,000 acres over the last two weeks, officials said.

The high temperature in Denver on Friday is in line with the seasonal average for July 25 but will not come close to reaching the all-time high for this date, according to weather service data.

There is a minor heat risk across Denver on Friday, but it will primarily impact people who are extremely sensitive to heat and don’t have a good way to cool off or stay hydrated, the weather service said. 

There’s a 30 percent chance of showers and thunderstorms in the Denver area on Friday, but that will be mainly after 3 p.m., meteorologists said. The chance for showers extends through about 7 p.m.

Tonight, expect the low to dip to around 61 degrees, the weather service said.