First of all, it's interesting to observe that August was the warmest month of summer statewide, and that's rare: it has only happened twice in the last century, in 1941 and 1959 (according to NOAA/NCEI data). Here's this summer's daily statewide temperature index from UAF (note that this is an index based on departures from normal, not absolute temperatures):
In 102 years of data, June has been the warmest month of the year in Alaska five times, including a tie with July in 2024. July is the warmest month in over 90% of years. Of course, this breakdown varies with region. Fairbanks more often sees June as the warmest month, and has never had August as the warmest month, but southern maritime locations more often see peak warmth in August (e.g. over 75% of years in Cold Bay).
August was also the first warmer-than-normal month statewide since last November, breaking a streak of 8 consecutive below-normal months (although April was essentially normal) - based on the 1991-2020 normal. The last time 8 months in a row were cooler than normal was in 2012, not long before the sudden reversal (which proved enduring) to persistent warmth in early summer 2013.
Here's the mid-atmosphere pressure map from August, showing that high-pressure ridging became a prominent feature across all of southern Alaska.
The ridge was fostered by, and also acted to reinforce, much above normal sea surface temperatures from the Sea of Japan to the waters south of the Aleutians. This is basically a negative PDO signal, although the warm pool is shifted slightly north compared to its classical position.
August warmth was most anomalous in northern and eastern Alaska: the North Slope was very warm indeed, and NCEI ranks the Southeast Interior division as the 5th warmest on record (but not as warm as 2023).
August rainfall was feast or famine, so to speak, with a sharp contrast between very damp conditions in the western interior and much drier weather to the south and east of Fairbanks. It was also very dry in the Aleutians, courtesy of the North Pacific ridge.
Sadly, the very warm and dry conditions in the southeastern interior allowed a damaging fire to occur in Tok. To quote Rick Thoman, "More than 40 homes in Tok were damaged or destroyed by the fire, making it one of the most destructive fires in terms of societal impacts in Alaska history".
The Tok fire illustrates the adage more often used in hurricane preparedness: "it only takes one". It's no comfort to those affected, but the statewide seasonal wildfire activity was far below normal this summer - only 89,000 acres burned, the lowest total since 1995.
The very inactive fire season is in some ways a surprise, because despite the overall cool weather in June and July, there was a lot of lightning for a 3-week period in late June and early July.
Here are some maps to illustrate the spatial distribution of this season's lightning and its departure from normal. The southeastern interior saw less lightning than normal, but a much larger area from the Y-K Delta to the western and northern interior was significantly more active than normal.
The Lower Yukon fire monitoring zone was the most unusually active region in Alaska, with a new seasonal record for total lightning strikes (data since 2012).
On the inactive side, the upper Tanana River region saw the most significant lightning deficit compared to normal:
The lack of significant fire growth in the wake of the June-July lightning onslaught can be mainly attributed to the wet spring, along with a notably cool May, preventing fuels from becoming very dry before the onset of lightning season. Of course the absence of really warm weather in June and July helped a lot too.
As one example of the "missing warmth" in Alaska's interior, Fairbanks only reached 81°F for the highest temperature of the summer; this has only happened a few other times in the period of record. The normal summer peak temperature in Fairbanks in recent decades is 88°F. In contrast, southeast Alaska reached unusually high temperatures in mid-August, and the period of record does not show any other year with such a contrast (i.e. peak summer temperatures around 5°F warmer in Southeast than in Fairbanks).
Wrapping up the discussion with some maps of the overall summer climate anomalies, we see that southern Alaska and the central interior were generally cooler than the 30-year normal, but not dramatically so in most locations.
A more significant anomaly is seen in the summer's total rainfall, which was well above normal in the southwestern mainland and far below normal in southeast Alaska.
NCEI's data shows the central and northern panhandle regions with the second lowest summer rainfall in the last 30 years (3rd percentile on my map) - 2004 was considerably drier. However, summers drier than this year occurred with some regularity prior to 1995, so the drought isn't quite as remarkable on a long-term basis. Here's a chart for the central panhandle division:
Summer sunshine was most abundant (relative to normal) in the extremities of Alaska - west, north, southwest, and southeast.
It's interesting to see the unusual combination of sunnier and wetter than normal in western Alaska; this happened because June (long daylight hours) was much sunnier than normal, and August (typically wetter) was much wetter than normal - and these two months dominated the respective seasonal anomalies.
Finally, for completeness - July was windy in southern Alaska, and August was windy in the southwestern mainland, but all three months were notably less windy than normal on the North Slope. With less breeze than normal, the mosquito season may have been an especially bad one for the long-suffering residents of the far noth.
