Alaska climate report: June jumped from cool to hot, hot, hot

Alaska climate report: June jumped from cool to hot, hot, hot

June began cool and wet but rapidly changed to hot and dry at the midpoint, with wildfires bursting out across the state, according to the monthly summary from the Alaska Climate Research Center.

The month also saw the first issuance of the new "heat advisory" by the National Weather Service. Unusually hot weather was previously noted to the public in "special weather statements," since no local criteria for heat existed.

"Alaska heat advisories will be issued for temperatures considered unusual for the local population," the ACRC summary reads. "This translates to temperatures above 80° F in the Southeast and a range of temperatures between about 75°F and 85°F in other parts of the state."

A National Weather Service fact sheetprovides additional information about the new heat advisory terminology.

The Alaska Climate Research Center, a part of the University of Alaska Fairbanks Geophysical Institute, released its June summary earlier this month.

June picked up where May left off - cool, rainy and even frosty at night in parts of the Interior. In some northern Brooks Range valleys, snowmelt hadn't even begun by early June - an unprecedented delay with no recorded snowmelt until June 10.

Things changed in the second week of June. Temperatures surged, triggering a rapid melt of the remaining snowpack. Rivers swollen by runoff flooded low-lying areas and washed out a portion of the Dalton Highway, cutting off all road access to and from Prudhoe Bay for four days until June 18.

A series of thunderstorms with frequent lightning strikes but without substantial precipitation kicked off the fire season between June 15 and June 20. The Interior had mostly below-average precipitation over prior weeks, allowing fuel to dry. The combination of available fuel and widespread lightning resulted in more than 160 wildfires over just a few days.

Other June highlights:

• Monthly mean temperatures in southern Alaska were mostly slightly cooler than average, while the northern half of the state was moderately warmer than the 1991-2020 climatological normal. The monthly temperature deviations for June range from plus 2.8 degrees Fahrenheit in Utqiaġvik to minus 2.6 degrees in Bethel.
• Interior Alaska had an unusually dry June, with only 38% and 39% of normal precipitation in Delta Junction and Fairbanks, respectively. Most of the precipitation recorded at these stations fell late in the month.
• Nome was the wettest station in relative terms, with 271% of normal. St. Paul Island was next, with 198%, followed by Homer and Cold Bay, both at 159% of normal. The western coastal stations saw substantial precipitation around mid-month.
• Arctic sea ice continued its seasonal decline and was at record low extent for the time of year. Ice extent around Alaska was slightly below normal. Total Arctic sea ice extent as of June 26 was 9.692 million square kilometers, compared to 11.813 million on May 26.

ADDITIONAL CONTACT: Martin Stuefer, director, Alaska Climate Research Center, mstuefer@alaska.edu

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