Now, back to the data. You can easily Google annual rainfall and learn that New York receives an average of ~44 inches compared to Seattle’s ~38 inches. Below are the averages I pulled from the past 26 years using the weather stations plotted below.
When we break down the numbers by month, we can see that New York receives more rain than Seattle except for four months of the year. We have uncovered our first fact: Seattle sees a higher total precipitation from November through February.
Diving in a bit deeper we can see the average hourly precipitation rate. On average, it is always raining harder in New York with the heaviest rain falling in summer months. To the contrary, the rate of rainfall in Seattle is essentially flatlined the entire year. Second fact: It rains significantly harder in New York than it does in Seattle.
This leads me to the question I was most interested in: How does Seattle receive more rainfall in the winter if the rainfall rate is always less than it is in New York? Of course, the answer is frequency. It rains impressively more hours per month in Seattle than it does in New York (except during the summer). In January, Seattle sees an average of ~160 hours with rainfall compared to only ~78 hours in New York. That is 50 percent more hours of the month that see rainfall in Seattle.
So why do people complain about the rainfall in Seattle so often? Because even though it doesn’t get the most rainfall or even the hardest rainfall, Seattle consistently gets rain more often than New York.
The next time I find myself in a pinch while arguing the nuances of Seattle's treacherous rain, I will feel confident in my claims that Seattleites truly are tough, resilient people who can withstand the worst of wet winters. I now have the data—the facts—to back up my opinions.