(Reuters) -Smoke from wildfires burning in three Canadian provinces covered about a third of the U.S. on Wednesday, forecasters said, but had little effect on air quality except in New England and parts of New York state and the Midwest.

More than 31,000 people were under evacuation across Canada on Wednesday as firefighters battled raging wildfires threatening towns and villages, authorities said.

Wildfire smoke was helping raise ozone to hazardous levels. No alerts have been issued, but the air quality may approach “code orange” levels again late Thursday afternoon in parts of the region, as it appears that the ozone factory will still be operating while the Canadian wildfire smoke persists in the skies over Philly.

Ontario Premier Doug Ford is pressuring Canada’s Prime Minister Mark Carney to ramp up tariffs against the United States after President Trump doubled tariffs on steel and aluminum earlier this week.

Prime Minister Mark Carney says Canada will take "some time" on its response to increased U.S. tariffs on steel and aluminum.

The Premier of Ontario, Doug Ford, announced plans to move $30 billion in manufacturing to Canada after new U.S. steel tariffs.

Canada’s Mark Carney calls the 50-percent tariff increase ‘illegal’, while Mexico’s Sheinbaum weighs countermeasures.