First day of summer brings worst day for pollen in the Pacific Northwest

PORTLAND, Ore. (KOIN) -- As it turns out, the first day of summer will be a not-so-fun time for allergy sufferers, especially if you live in the Pacific Northwest.

According to pollen.com, large swaths of Oregon and Washington are affected by medium-high levels of pollen, including the Portland metro area.

But the most affected areas, showing the highest levels in the United States, begin in central Oregon near Bend, then extend west, moving through Eugene and all the way to the coast.

Grass allergens are the top culprit and according to KOIN 6 meteorologist Josh Cozart, many of Oregon’s grasses grow well into the month of June and typically slow their pollination period by the start of July. Then most grasses are cut and the seed is harvested by the Fourth of July.

Thus, the end of the growing season for Oregon grasses should mark the end of the bad allergy season in the Pacific Northwest.