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An unofficial nickname for Washington is the \u201cEvergreen State\u201d; the term is included on our vehicle license plates. But we actually enjoy a Mediterranean climate with wet winters and dry summers, and much of the state is more brown than green during the summer. That must have been especially true in July 1960, which appears to have been the driest month in state history dating back to the 1890s. Here we take a look at that particular month as a follow-up to our piece in this newsletter a year ago, which focused on the record warmest month of July 1985. <\/p>\n

The ten driest months in WA state during the instrumental record are indicated in Table 1. The record lowest amount from a statewide perspective was 0.03\u201d in July 1960, just under the 0.04\u201d estimated for July 1922. These values are both less than 5% of the 20th century average precipitation during July, which is 0.90\u201d for the state as a whole. It turns out it was actually drier on the west side of the Cascades in July 1922. But all of the climate divisions of the state were exceedingly dry in July 1960 (ranging from 0.01\u201d in the Puget Sound Lowlands to 0.05\u201d in the East Slopes Cascades region). Some stunningly low amounts of precipitation occurred in spots that normally get a fair amount of rain. For example, in the coastal region of WA, Forks checked in with only 0.04\u201d and Hoquiam got completely shut out with 0.00\u201d. The 1981-2010 climate normal for Forks and Hoquiam in July is 2.47 and 1.14\u201d, respectively. There were some isolated locations that were wetter, of course. While we have not conducted an exhaustive review of all the possible station records, the highest totals we found were 0.48\u201d at Paradise Ranger Station at Mt. Rainier on the west side, and 0.22\u201d at Conconully to the east of Cascade mountain crest. El Ni\u00f1o-Southern Oscillation (ENSO) has only modest impacts on our summer weather, and ENSO certainly cannot be blamed for the lack of rain in July 1960. The Nino3.4 index was 0.2, and the Pacific Decadal Oscillation was -0.27. During July 1960, as well as many of the other months on the statewide driest list, these two indices commonly used to characterize the large-scale state of the climate of the North Pacific were in the neutral category. <\/p>\n

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Not surprisingly, July 1960 was also hotter than normal, specifically the 12th warmest month on record. The photo shown below shows how some folks beat the heat (http:\/\/www.historylink.org\/index.cfm?DisplayPage=output.cfm&file_id=5630) in Grayland, WA. The month of August 1967 also made both top-ten lists. While dry and warm tend to go hand in hand during the summer, the correspondence is not that tight with regards to extreme months. For example, the mean temperature during the 2nd driest month of July 1922 was only 1.2\u00b0F above normal, and the precipitation during the 2nd warmest month of July 1998 was actually 0.27\u201d above normal. <\/p>\n