July Climate Data

Last month was the wettest July in recorded climate history for Alaska (1925-present), with a statewide average precipitation of 5.2 inches, according to NOAA/NCEI.  The previous record was 4.8" in 1959.

The contrast with June was dramatic, as June was tied for 3rd driest on record statewide.

As we would expect, the flow was more westerly than normal over most of Alaska, courtesy of above-normal pressure near and south of the Aleutians, and an unusually strong trough over the Arctic Ocean (nearly opposite to the June pattern).  The maps below show the 500mb height and 850mb westerly wind anomalies for the month.

It's interesting to see that above-normal westerly flow extended all the way from eastern China and Japan to the Bering Sea and Alaska, suggesting that moisture was transported up from the subtropics by southwesterly flow.  The wind vectors for the month (absolute values, not anomalies) support this idea:

The abundant rainfall was quite widespread, though not universal.  The upper Tanana River valley was dry, as was Kodiak Island, and the extreme southern panhandle was also a bit drier than normal, according to ERA5 data.

As for temperatures, the vast majority of Alaska was cooler than the recent 30-year normal, and some places were notably cool - for example, Bethel had its coolest July since 2012.  However, the statewide July mean temperature would have been perfectly normal about 50 years ago.

Wind was significantly above normal for most areas to the north of the Alaska Peninsula, and sunshine was in short supply for most of the state as well.  The contrasts with June (see here) are all very striking.