How Rainy Is Seattle? It's Not Even in the Top 30 of Major U.S. Cities

How much does it rain in Seattle? It rains enough that a company (based in Seattle, of course) developed a product called a RainGlobe, which is like a snow globe, except it rains inside. (I bought two of them and thought they were pretty cool until the water turned yellow.)

Given Seattle's rainy reputation, it must be one of the wettest cities in America, right? Wrong. Not even close. In fact, Seattle doesn't even rank in the top 30 for precipitation among the nation's 50 largest cities.

To perform this analysis, I combined data from two sources: (1) Wikipedia's page on the 383 metropolitan statistical areas in the United States; and (2) a website called Current Results that features aggregated weather data. The first chart below depicts the wettest cities ranked by total precipitation:

At 37.7 inches of precipitation annually, Seattle ranks 32nd among the nation's 50 largest cities. Notice that most of the cities with more rainfall are located east of the Mississippi River, as shown in the map below made by climatologist Brian Brettschneider.

Source: Brian Brettschneider

How is it possible that Seattle has such a rainy reputation if it's not even remotely one of the wettest cities in the country? Well, the rain in Seattle is sort of like the mist in the grocery produce aisle. It rarely rains hard; instead, it has a (seemingly) never-ending drizzle that keeps the city wet almost all-year round. (The dry season is the summer, which lasts from roughly July to early October.)

So, Seattle's reputation is totally deserved because of the number of days in which it rains. Yet, Seattle only comes in at #5 by this ranking. Believe it or not, there are cities with even more rainy (or snowy) days: Buffalo, Portland, Cleveland, and Pittsburgh.

Portland didn't surprise me. It's Seattle's "little brother" down the road, and the weather there is very similar to ours. But Buffalo, Cleveland, and Pittsburgh? Really?

Apparently, those cities are just about as dreary as Seattle. Climatologist Brian Brettschneider also made what he called the "Dreariness Index," which factors in total precipitation, the number of wet days, and cloudiness. By this metric, Seattle and Buffalo are tied for #1, while Portland and Pittsburgh are tied for #2. 

Source: Brian Brettschneider

Yes, Seattle is a dreary place -- but I like it that way. What can I say? I'm a pluviophile.