Most of Alaska was cooler than normal in May with for the conspicuous exception of Northwest Arctic Borough and the Seward Peninsula. Utqiaġvik had the coolest May since 2010, Juneau and Cold Bay the coolest since 2012 and Anchorage and Fairbanks coolest May since 2013. On the other hand, Kotzebue had the mildest May in several years.

More notably, for the second May in a row, there was a lack of any really warm weather in the state. At Utqiaġvik, the high temperature for May of 29F was the lowest since 1952 and second lowest in 106 years of climate observations. At Cordova Airport, the high of 58F was lowest May maximum since 1965 and at Kodiak the high temperature was 54F, the lowest since 1966. At Anchorage, the May high was 60F, the lowest since 1980. In the Interior, many places had the lowest May high temperatures since 2000. The highest reliable temperature in the state in May was 74F at Hydaburg on May 4th. The lowest temperature was -1F on May 9th at the NOAA Climate Reference Station at the Barrow observatory northeast of Utqiaġvik .

May precipitation was above normal over much of mainland Alaska except for the west and North Slope. The northern Gulf of Alaska coast was especially soggy. In the Prince William Sound area this was the wettest May since 1989 and most of the Cook Inlet region saw 2 to 3 times the normal rainfall. Most of the Interior had above normal rainfall, but western Alaska and the North Slope were generally drier than normal, at least based on the comparatively few available observations. There were a few days with thunderstorms in the Interior and at least a few places in on or near the Bering Sea coast also had a day with thunder, including Hooper Bay on May 25 and Koyuk on the 27th.

Snowfall totals were not excessive in May, with 7.8 inches at the 2100 feet MSL Eagle 7.8 SE CoCoRaHS station the highest reported. However, snowfall at moderate elevations in Southcentral were widespread late in the month. Several inches of snow fell on the hills above Homer on May 23, and on May 30 there were a few inches accumulation in the early morning hours along the higher elevation sections of the Glenn Highway between Chickaloon and Tazlina (Fig. 3).

I wrote in some detail on Alaska river break-up as of May 8 and May 16. In summary, break-up was a few days later than normal in most area but was complete south of Brooks Range by the end of May. However, break-up had barely started on the North Slope. A State of Alaska disaster declaration was issued for flooding on the Draanjik River at Chalkyitsik and Hughes on the Koyukuk River early in the month and then the area on the Yukon River from Grayling to Russian Mission was added to the declaration on May 21. Holy Cross was perhaps the most severely impacted community, with a number of homes and the entire airstrip inundated for several days with water impounded behind an ice jam downriver of the community. Some communities, such as Bethel, had minor or “typical” break-up flooding.

Wildfire was not much of an issue in Alaska in May. At the end of the month about 900 acres had burned, which only 15 percent of the 1993-2025 median.

Sea ice extent was below the 1991-2020 baseline normal all month in the Bering Sea. Very unusually though, a small area of ice persisted to the end of May near Togiak Bay, southwest of Cape Newenham (Fig. 4). A large area of open water developed beyond the shorefast ice along the western North Slope coast. This was the most open water at the end of may in Chukchi Sea since 2022.

Between the spring sea ice and a cool weather pattern, May average sea surface temperature were way below normal in the southeast Bering Sea and adjacent areas on the Pacific side of the Alaska Peninsula and eastern Aleutians (Fig. 5). This contributed to several days of exceptionally cool weather the last week of May, with temperatures remaining in the 30s from Port Heiden to Cold Bay May 27-28th. Sea surface temperatures were also generally below normal in Gulf of Alaska from Yakutat westward, but were near to slightly above normal offshore of Southeast Alaska.