Colorado weather: Red flag, heat and smoke advisories active statewide

Katie Langford and Lauren Penington, The Denver Post on Aug 6, 2025

By clicking submit, I authorize Arcamax and its affiliates to: (1) use, sell, and share my information for marketing purposes, including cross-context behavioral advertising, as described in our Privacy Policy , (2) add to information that I provide with other information like interests inferred from web page views, or data lawfully obtained from data brokers, such as past purchase or location data, or publicly available data, (3) contact me or enable others to contact me by email or other means with offers for different types of goods and services, and (4) retain my information while I am engaging with marketing messages that I receive and for a reasonable amount of time thereafter. I understand I can opt out at any time through an email that I receive, or by clicking here

DENVER —Dangerous fire conditions, soaring temperatures and smoky skies across Colorado prompted severe weather alerts for parts of the Western Slope, Front Range and Eastern Plains on Wednesday.

Temperatures are expected to reach 100 degrees in Denver, Boulder, the western metro and Fort Collins, National Weather Service forecasters said in a heat advisory.

If Denver hits 100 degrees on Wednesday, it will tie its heat record for Aug. 6, set in 1980, according to weather service records.

The city also has a chance to break its record for the hottest Aug. 7 if temperatures hit 100 degrees on Thursday, as forecasted. The current record of 99 degrees was also set in 1980.

The heat index in El Paso, Pueblo, Fremont, Crowley, Otero, Bent and Prowers counties is expected to range from 94 to 100 degrees, according to the agency. The heat index, or “apparent temperature,” is how hot it feels outside when considering both humidity and temperature.

People can prevent heat-related illnesses by drinking plenty of fluids, staying in an air-conditioned room, staying out of the sun and checking on relatives and neighbors to make sure they are doing the same.

Gusty winds, low humidity, dry fuels and high temperatures are all contributing to critical fire danger across the Western Slope, weather officials said in a red flag warning. Firefighters are battling active wildfires in Rio Blanco, Delta and Dolores counties.

The warning is active from 11 a.m. to 8 p.m. for parts of Moffat, Routt, Rio Blanco, Garfield, Mesa, Montrose and San Miguel counties, where relative humidity is as low as 8% and wind gusts could reach 35 mph.

A second red flag warning is active for parts of Boulder, Larimer, Grand, Jackson and Summit counties because of gusty winds and low humidity, forecasters said. Critical fire weather conditions will likely continue through Friday.

“Conditions will be favorable for rapid fire spread,” officials said in the alert. “Avoid outdoor burning and any activity that may produce a spark and start a wildfire.”

Smoke from the Elk and Lee fires in Rio Blanco County is causing poor air quality throughout the state, according to the Colorado Department of Public Health and Environment.

“The thickest smoke will originate from the Rio Blanco County fires, and arrive on the Front Range each late afternoon and evening, settling across the plains overnight,” weather service forecasters said Wednesday.

An air quality health advisory is active for most of the Front Range and Western Slope until Thursday morning, and periods of “moderate to heavy smoke” are possible.

Impacted counties include Denver, Jefferson, Douglas, Arapahoe, Adams, Broomfield, Boulder, Larimer, Weld, Clear Creek, Grand, Eagle, Jackson, Gilpin, Garfield, Rio Blanco, Routt and Dolores counties.

If visibility is less than 5 miles, smoke is at unhealthy levels and people should remain inside, especially those with health conditions like heart disease or respiratory illnesses.

_____