July 2025 Arctic and Alaska Climate Summary
Air and Ocean Temperatures and Precipitation
This post focuses on temperatures and precipitation during July. I posted about July 2025 wildfire, sea ice and Greenland ice sheet area melt here.
July has, climatologically speaking, the highest average air temperature of any month of the year for virtually all land areas in the Arctic as well as over the pack ice. The only exceptions being some island where the August average temperature is slightly higher than July. July precipitation for the Arctic is only the third highest, lower than August and September, though with differences in the timing of peak precipitation between the Atlantic (September) and Pacific (August) sides of the Arctic.
Arctic Air Temperatures
July temperatures for the Arctic (land and seas north of 60°N) overall were pretty typical for recent years but with a lot of regional variability. Figure 1 shows temperature departures from the 1991-2020 average based on the ERA5 reanalysis. As always in mid-summer, air temperatures over the ice pack are usually close to freezing as heat goes into melting the surface snow and ice, so significant departures from normal are rare and usually indicate unusually low concentration sea ice. Overall, 67 percent of the Arctic had above normal temperatures in July. For land areas it was slightly lower at 63 percent above normal.
The Nordic Arctic was especially warm. For Norway this was the third warmest July on record, and across the region the duration of the warmth was remarkable. Mika Rantanen with the Finnish Meteorological Institute (FMI) reported on BluesSky that the heat wave that began in early July “…is probably not only the longest heatwave in Lapland, but also the longest heatwave ever observed in Finland.”
A noteworthy extreme temperature was reported on July 22, when Habarova, in the northern Sahka Republic, Russia, on the lower Lena River (northwest of Tiksi), reported a high temperature of 32.1°C. This may be the highest temperature on record in the Arctic north of 72°N.
The July average temperature time series since 1950 for the Arctic is shown in Fig. 2. This was the sixth highest July average temperature and very close to the rapidly increasing average. Over Arctic lands, the July average temperatures was the lowest since 2022 and the 11th highest since 1950, though still warmer than every July prior to 1991.
Sea surface temperatures
Summer ocean surface temperatures in the Arctic are strongly controlled by the presence or absence of sea ice. Figure 3 shows the sea ice temperatures difference from the 1991-2020 baseline average. Areas where the July average sea ice concentration exceeded 15 percent area masked. The Kara Sea stands out as especially warm relative to average, as does the Norwegian Sea. Interestingly, the Barents Sea (north of the European Arctic) was not especially warm except around Svalbard. On the Pacific side of the Arctic, the eastern Bering Sea was also cooler than average.
Arctic Precipitation
Precipitation is always much more variable than temperature, but overall for the Arctic this was the lowest July average precipitation since 2009. Per Fig. 4, this was the result of below normal precipitation between 70°N and 80°from the Laptev Sea eastward to the Canadian Arctic Islands as well as the Norwegian Sea and northern Nordic Arctic.
Because so much of the significantly drier than average area was over high latitude oceans, it’s unsurprising that precipitation over Arctic land areas was the lowest only since 2022.
Alaska Temperatures
July temperatures overall were near to a bit above normal in most Alaska, though nothing really of note. Figure 5a shows the ERA5-based departures (°F) from the 1991-2020 baseline, which are largely, though not entirely, in line with site specific observations, shown in Fig. 5b. Reliable temperature extremes at low and moderate elevations (below 3300 feet/1000 meters MSL) ranged from 93F (33.9C) at Dahl Creek near Kobuk on the 5th to 26F (-3.3C) at Imnaviat Creek in the Brooks Range.
The most notable event during July was the heatwave early in the month in northwest Alaska. As shown in Fig. 6, temperatures in the upper 80s and lower 90s (above 30°C) were widespread at low elevations from the northern Interior westward into Northwest Arctic Borough. On the North Slope, temperatures were also widely in the 80s except on the Beaufort Sea coast.
Between the Yukon River and Brooks Range there are hardly any long-term climate sites, so we can’t be dogmatic, but temperatures in the lower 90s are not unprecedented. For example, in the Kobuk and Noatak valleys during the June 1991 heatwave, the cooperative observer at Ambler reported two days with highs in the 90s, including 93F (33.9C) on June 22, while the cooperative observer at the old Noatak River Fish Hatchery, below Noatak, reached 92F (33.3C). Temperatures this high in the Koyukuk valley are slightly more common, e.g. Bettles had 13 days in the preceding 50 years with highs in the lower 90s.
The western North Slope is a climate data desert, with no observations inland and only scattered observations over the decades at Wainwright and Point Lay on the coast. With that major caveat, the high temperatures of 82F (27.8) at Point Lay and 80F (26.7C) at Wainwright are higher than anything their very incomplete records.
Alaska Precipitation
Precipitation in July was mostly near to below normal (fig 7a), though with several regional exceptions, e.g Kodiak Island, Bristol Bay, and the lower Yukon valley.
The site-specific percent of normal percent precipitation (Fig 7b) shows a more nuanced view of July rainfall in the Interior, where most of the precipitation fell in convective showers, and so there was considerable variation in short distances.
My hunch (and that's all it is- just an uneducated guess) is that the Habarova high temperature may be increasingly common in that part of the Arctic. Do prevailing summer winds ever carry smoke from the boreal forest fires northward? It's probably fairly rare but it would be interesting to know if it ever happens.