Sunny summer days may not be quite as bright this year as smoke from wildfires burning across Canada occasionally spreads across the United States, resulting in hazy conditions and poor air quality.

Ranch Fire initially started 2:33 p.m. June 10 in San Bernardino County. It has burned 4,293 acres after being active for two days. As of Thursday evening, the fire crew managed to contain 50% of the fire. However, investigations into the cause are ongoing.

Toxic air spreads hundreds or even thousands of miles from where wildfires burn. Last week, Chicago felt the sting—and warnings weren’t enough to protect health.

AccuWeather long range meteorologist Paul Pastelok said long-lasting stretches of deep blue sky may not return to the Northeast for weeks, or possibly even months.

By Ed White WINNIPEG, Manitoba (Reuters) -World leaders may face smoke warnings when they gather next week in Alberta as wildfires burned out of control across much of Canada and caused the country's second-worst fire season in decades.

On this Line One, join Dr. Justin Clark for a discussion about the health impacts of wildfire smoke and volcanic ash.

Claro Fire broke out near Lake San Marcos, California, sending smoke across Carlsbad, La Costa Oaks, and Encinitas. Evacuation order has been issued.

With seasonal wildfire smoke rolling into Calgary, residents often have questions about all the things that come with it.