60 years of climate change will do that. Not sure anything approaching a 1964 result would be possible today. It's actually the coldest calendar year in PDX history, even colder than 1955 by about 0.4 degrees.
1964 was also at least moderately impacted by the Agung eruption, so it had a lot going for it.
It was also a volcanic year in the middle of a multidecadal global cooling cycle. Wouldn’t try to derive predictive value from it.
But it goes to show how anomalous the circulation regime is this year. It’s reflected in the off-the-charts -PDO and +AMO, in addition to in-situ -PMM following a strong niño, which is very rare (in the post-WWII era only 1973 managed to pull that off, and it had a cold Atlantic, unlike this year).