Highlights

The birch pollen count exceeded 4,200 on May 2nd in Fairbanks, a new local record, which also approached the world record of 4,696 from Denmark in 2014. The Anchorage pollen count for the 3rd was 210, but had been higher the week before. A count of 175 over a 24-hour period is considered high for pollen. Also on the 3rd, avalanche reduction efforts were deployed along milepost 241 to 247 of the Dalton Highway. This action was repeated on the Dalton Highway on the 6th and 10th. On the 5th a major wildfire in Canada resulted in the closure of the Alaska Highway near milepost 80. The Alaska Highway is the major land access to Alaska from the lower 48 states. On the same day a new coal seam fire flared up near Healy, bringing the total for the year to four coal seam fires burning in the area.

A flood warning was issued for Deering when a combination of an ice jam, recent rains and snow melt pushed the Inmachuk River to flood the airport on the 11th. By mid-month burn permits were suspended for Interior and Railbelt areas due to dry and record warm weather, while Red Flag warnings were issued for the Upper Tanana River and Forty Mile areas. Anchorage issued a fire danger alert on for the 15th and 16th due to very warm weather and high winds. Northway and Eagle reported pea sized hail also on the 25th from an intense thunderstorm.

Snow was reported from Eagle in the Interior to Denali National Park in the Alaska Range as an arctic cold front pushed the recent, record warm air mass out and collided with a wet air mass from the Gulf of Alaska. Temperatures in Tok went from over 80°F to below 31°F with snow, the light frost killing some vegetation in gardens. The Denali Highway was opened to traffic from the Parks Highway to the Richardson Highway on the 18th. Flood watches were issued for the Colville River due to ice jams on the 18th, and high water continued in the area till the end of the month. The next day the Top of the World Highway was opened to traffic. A flood advisory for flooding along the Kuparuk River at the Dalton Highway Bridge due to an ice jam was issued on the 22nd. Snowfall was reported in the Chugach Mountains near Anchorage, in Denali Park in the Alaska Range, and Brooks Range on the 22nd.

A wildfire in Anchorage near Eagle River broke out on the 27th and was fought aggressively on the 27th and was reported 100% controlled the next day. Burn suspension was put in place for the areas of Tok, Fairbanks and the Mat-Su area due to fire danger on the 29th. A major wildfire, the Medfra Fire, 50 miles southeast of McGrath, was reported on the 29th, and smokejumpers, two air tankers, and other fire crews were called in due to the danger. By the 31st, the Medfra Fire had merged with another fire as was estimated at 8,000 acres. This fire is one of a number of "hold over fires" from the record fires season last summer. By the end of May at least 16 "hold over fires" had flared up.