Smoke from Canadian wildfires burning more than 500 miles away has again reached Smithfield.

The National Weather Service, at 10:39 a.m. on June 29, issued a hazardous weather outlook for Isle of Wight and Surry counties, warning of “unhealthy” air quality.

The U.S. Air Quality Index map, which measures ground-level ozone and particulates in the atmosphere on a zero-to-500 scale, showed Smithfield in the “red” zone as of 11 a.m.

Areas with an AQI of 50 or below are considered “good” and color-coded green, and those in the 50 to 100 range are shown in yellow as “moderate.” Those with an AQI of 100 to 150 are color-coded orange and are deemed “unhealthy for sensitive groups” such as people with respiratory or heart conditions. An AQI of 150 to 200 is color-coded red and deemed unhealthy for everyone.

The U.S. Environmental Protection Agency’s airnow.gov website advises everyone in red zones to limit their time outdoors and choose less strenuous outdoor activities.

According to NWS Meteorologist Jon McGee, wind patterns should be “less favorable” by tomorrow for bringing smoke down from Canada, but the Smithfield area will still likely be in the yellow or orange zone.

June 29 marks the second day this month that Smithfield’s air quality has crossed into the red zone due to smoke from Canadian wildfires.

On June 7, Smithfield’s AQI peaked at 168 and remained in the yellow for two weeks after. As of noon on June 29, Smithfield’s AQI was at 154.