The Seattle winters are wet (and this week even snowy) but the Emerald City has far better weather than Boston during the baseball season.
Here are the average monthly precipitation totals (in inches) and average high temperatures:
March: BOS: 4.33, 45; SEA: 3.70, 54
April: BOS: 3.74, 56; SEA: 2.68, 58
May: BOS: 3.50, 66; SEA: 1.93, 65
June: BOS: 3.66, 76; SEA: 1.54, 70
July: BOS: 3.43, 81; SEA: 0.67, 76
August: BOS: 3.35, 80; SEA: 0.87, 76
September: BOS: 3.43, 72; SEA: 1.42, 71
October: BOS: 3.94, 61; SEA: 3.46, 60
It's the humidity that can make the Boston summers oppressive. As a 17-year-old hitchhiker from Iowa, I made my first trip to Boston during a heat wave that I remember as 100 degree temperatures with 99 percent humidity*. My second trip to Boston came in August 2010 when my friends and I encountered torrential rains in Rhode Island driving up to Fenway Park from New York. The exceedingly polite usher wiped the rain off of our bleacher seats at Fenway. On my final trip to Boston a cold rain drenched me at the Head of the Charles Regatta in October 2016 before the skies cleared and the temperature plummeted the following day.
Boston is a fine city but the weather is not my cup of tea.
* an internet search revealed that the high temperature in Boston that day in July 1973 was 95 degrees with 71 percent humidity:(