They say we may receive some lowland snow next midweek but it’s highly uncertain right now. And we’re running out of winter this late in February. I always like a good snow, but by this point in the winter I’m ready to move onto spring and lighter days with a higher chance of sun.
So how much snow do we receive in Seattle typically. Looking at the historical records, by year, it’s not uncommon. But it’s also not a lot of snow either. In the last half of last century, we received approximately about 11.6 inches of snow per calendar year. Since 2006, it has been about 7.24 inches per calendar year.
A side note: I’m specifically stating calendar years as opposed to “winters” or “seasonal years”. Snow is a winter phenomenon in Seattle for the most part and winters typically cover parts of two calendar years, running from November through the following February. So, in a lot of ways, it would make sense to use winters or seasonal years to describe accumulated snow. But there is a bit of data gymnastics involved introducing new calendar constructs and developing the charts as such requires extra work often with labelling winters as, say 2022-23. So, I’m sticking with using calendar years in this discussion since the data is delivered grouped in years. Therefore, when speaking of, say, the amount of snow received in 1993, I’m speaking of the accumulated snow which most likely occurred in January, February, November, and December of 1993.
Seattle-Tacoma International Airport Records
Figure 1 shows the cumulative snow by calendar years at Seattle Tacoma International Airport (KSEA). Full year records at SeaTac begin in 1948 and continue through today. SeaTac averaged about 11.6 inches of snow from 1948 through 1995, a period of 48 years Several years saw no or very little snow, about nine in total, a little less than 19% of the years. On the other hand, 11 years saw more than 20 inches of snow, close to 23%. There were sever whopper years: 1950 saw about 60 inches of snow. This was a cold period, and the massive snow year was bookcased by snowy years, roughly 25 inches in 1949 and 27 inches in 1951. They must’ve sold a lot of snow shovels in those years.
Figure 1 also shows something else: missing data for an extensive 109-month period from the National Oceanic and Atmospheric Administration (NOAA) and National Weather Service (NWS) data records for the SeaTac site. The year 1996 stands out. During January and February 1996, Seattle received about X.X inches of snow. That is what is reported on their csv data extracts for 1996. However, anyone around in Seattle during December 1996 knows we received quite a bit of snow in the end of that month. However, the NOAA/NWS written records on standard forms and published in monthly PDF reports do account for that December snow (sort of – too much to go into here). So, I’ve added it in a gray bar on Figure one for 1996. Similar monthly published PDFs show approximately 5 inches of snow for 2001 unaccounted for in the standard database extracts, so I’ve added a gray bar for 2001 as well. Suffice it to say that the data between October 1996 and October 2005 should be taken with a grain of salt.
Figure 1. Seattle accumulated snow by year, 1948 – Present.
Click to zoom.
Other Local Weather Stations of Record
Seattle has several other local weather stations of record. Several of these are even located in the city proper. SeaTac is about 15 miles SSW of downtown Seattle. And some of these stations have or had records extending well before SeaTac’s, which only go back to 1948.
These stations and their period of records for snowfall are listed below:
(a) Seattle Naval Air Station, STA USW00024244, NE Seattle, 1929-1970;
(b) Sand Point Weather Forecast Office, STA USW00094290, NE Seattle, 1986-Present;
(c) The University of Washington Weather Station STA USC00457478, N Seattle, 1909-1983;
(d) Portage Bay Weather Station, STA USW00024281, N Seattle, 1894-1998; and
(e) Boeing Field Seattle, STA USW00024234, S. Seattle, 1948-Present (but not all for snow).
Figure 2 shows all these stations and their respective recordings of measurable snowfall from 1894 through the present, depending on each station. So, some of that missing data in Figure 1 could be somewhat covered for by two of these stations, Portage Bay (partially) and Sand Point (for the entire period) though, in general, they are 20-25 miles from Seattle-Tacoma Airport.
Figure 2. Accumulated snow in Seattle from various recording stations, 1894 – present.
Click to zoom.
Figure 3 thru Figure 8 highlight snow records for each of these stations individually and the period of records they kept respectively.
Figure 3. Seattle Tacoma International Airport, KSEA (current).
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Figure 4. Seattle Naval Air Station (historical).
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Figure 5. Sand Point NOAA/NWS Weather Forecast Office (current).
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Figure 6. University of Washington (historical).
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Figure 7. Seattle Portage Bay (historical).
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Figure 8. Seattle Boeing Field (historical for snow).
Click to zoom.