Spring blossoms, dusty streets, distant fires and a lack of rain combine to create hazardous respiratory conditions.

A UN official says it looks from the air like parts of Mozambique were "run over by a bulldozer".

Pollen from birch trees was carried along with dust from the Sahara Desert on strong winds that originated in Eastern Europe.

Gallery | The fires, which were swept in from Mongolia by high winds, have caused almost $9.4 million in damage.

The Arctic Sounder - Serving the Northwest Arctic and the North Slope

The death toll from a storm that crashed into southeast Africa last month has risen above 1,000, with more than 4,000 cases of cholera reported among survivors in Mozambique, the hardest-hit country.

Why air quality is worse at different times of day and how you might be violating city code with your leaf blower.

Alder catkins (the pollen-rich flowers on alder trees) haven't reached their peak yet, but there are a lot of them. There can be four to five million pollen particles in a single catkin.

The tragedy came after several days of dire warnings about the dangers of river travel due to an unusually early warm-up. Search and rescuers crawled onto weak ice, open water all around, to help retrieve the survivors.

Two four-wheelers carrying five men leaving Bethel broke through needle ice on the upper end of Church Slough on Sunday night. Two of the men died, while three others were treated for hypothermia in Bethel.

A sheriff and his two daughters were injured near Lake City in southwestern Colorado after an avalanche destroyed their home Tuesday morning.

Crews are working to free multiple cars that are trapped by an avalanche on Highway 91 near Copper Mountain, the Colorado State Patrol has confirmed.

A severe heat wave is sweeping across parts of Punjab, with temperatures reaching up to 44 degrees Celsius on Monday. In different cities, including Gujranwala, Sialkot, Malakwal and Sambrial, reported that the scorching heat reduced traffic on roads, leaving markets deserted with people preferring to shop in the evening. People traveling on motorcycles and public transport are also facing a tough time.

Ellicott City was devastated by heavy rain Sunday, just two years after the historic city in Howard County was forced to recover from another flash flood.

On Sunday, both the cities reached 95 degrees, edging out previous highs of 94 degrees for May 27 set in 2012 for Madison and 1911 for Milwaukee.

Shellfish in the Puget Sound tested positive for the prescription opioid oxycodone, and this was not the only drug found by the Washington Department of Fish and Wildlife.

Military help is on the way to B.C. communities ravaged by floods, as rivers rise and more people are forced out of their homes around the province.

Washington state Gov. Jay Inslee proclaimed a state of emergency Saturday for counties in the eastern part of the state