Looks like a convenient approximation for figuring out what's up worldwide, with yearly charts of monthly minimum and maximum temperatures.  It sort of covers the wild fluctuations at Buxton in winter.  Uses satellite data only. Seems handy for showing tourists what to expect.

https://www.seatemperature.org/

Surfline provides roughly the same info (possibly with more hands-on data) and if you dig around, Magic Seaweed has its useful spot guides.  Rutgers lets you look at archived satellite data.