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by piffey 3046 days ago
Perception is a funny thing. Average annual precipitation for each city and sunny days per year:

Boston: 43.76in / 137 days

Seattle: 34.1in / 152 days

https://www.usclimatedata.com/climate/boston/massachusetts/u...

https://www.usclimatedata.com/climate/seattle/washington/uni...

2 comments

People do form weird perceptions, especially from short trips to places they don't know well, but your numbers are wrong.

137/152 are the number of days w/ precipitation, not sunny days. ie, Seattle has less rain, but more days of precipitation. This is typical comparing Seattle with many other cities: less rain total, but spread over more days.

Those more days are concentrated in winter, more so than in is typical in other parts of the country. If you look at the "hours of sunshine" stat over a whole year in your links, the typical seasonal change people complain about in the PNW is right there: Apr - Sep are similar, but Nov - Feb Seattle gets half as much hours of sun.

The concentration of gloomy drizzly days in winter is quite real.

It also doesn't help that the Seattle rises so late and sets so early for a couple of months during the winter, leading to more feelings of gloom.
From the same dataset:

Hours of sunshine during winter months (Dec + Jan + Feb): Boston: 464 Seattle: 235 (-50%)

Annual hours of sunshine: Boston: 2615 Seattle: 2019 (-23%)

so it's accurate to say that Boston is sunnier than Seattle and much sunnier during the winter.

And that's not silicon valley... say Mountain View, CA: - 560+ hours during winter months - 3,070 annual

https://weather-and-climate.com/average-monthly-Rainfall-Tem...