DENVER (KDVR) — The Colorado Department of Public Health and Environment says moderate to heavy smoke will be possible across much of the state on Friday.

According to IQAir’s air quality rating on Friday morning, Denver ranked in the top five for worst air quality in the world.

The CDPHE has issued an air quality health advisory alert for the Front Range and Denver metro area. It will be in effect until 4 p.m. on Friday.

What is causing the smoke?

The smoke is coming from several large wildfires burning in Canada, which is causing smoky skies across multiple states, including Colorado.

Is the smoke dangerous?

Will the level of smoke be dangerous for your health? Here’s what the CDPHE said you should know.

“If smoke is thick or becomes thick in your neighborhood you may want to remain indoors. This is especially true for those with heart disease, respiratory illnesses, the very young, and the elderly. Consider limiting outdoor activity when moderate to heavy smoke is present. Consider relocating temporarily if smoke is present indoors and is making you ill,” CDPHE said.

The CDPHE said that if visibility is less than five miles in smoke in your neighborhood, smoke has reached levels that are unhealthy.

Weather forecast

Keep an eye on the weather forecast for things like fire weather watches and warnings, or red flag warnings. You can see active weather alerts here.

Be sure to download the free Pinpoint Weather App to stay up-to-date with the newest weather data as it comes in and to get important alerts straight to your phone.