Interesting climate for sure. An incredible 143” of snow per year and the average highs at least approach 70 in summer. I figured their summers would be more like Scotland. Boost the average high by 10F or so during MJJAS and increase the number of sunny days during that time and you’d have my ideal climate.
I don't know what to tell you, other than that May isn't supposed to be a wall-to-wall sunfest with July like rain totals. These troughy interludes are totally normal for this time of year. Not to mention that there still has been plenty of sun even with our cooler days, and May finished both warmer and drier than our new 1991-2020 normals.
And, not that I'm in any position to lecture anyone here about "not freaking out", but dude, you genuinely sound really upset. Which is interesting considering this spring has been better than normal for your standards. I don't know how to come to any conclusion other than that the 2013-present warm period has totally skewed your expectations of what to see from April-October.