The white fluff all over your yard is simply cottonwood seeds. The continued dry conditions, with high temperatures and low relative humidity, along with the normal spring winds are serving to spread the seeds faster, higher and farther than usual this year.
The seeds are not pollen, so should not be contributing to allergies, but it is prime pollination season for conifers, according to Environment Canada.
The Ministry of Forests agrees. The level of pollen Fort St. John is currently experiencing is from spruce trees. Because last year was so dry, it stimulated spruce cone production, and as a result there is a lot of pollen about this spring.
The pollen is the yellow dust one finds covering vehicles in the morning, and causes itchy, watering eyes, and runny noses for many residents throughout the Fort St. John area.