colweather.org.uk

I have heard from a few people that their perception is that Springs are getting colder.

I assume they mean over the last few years, but the attached graph for Plymouth over a rather longer period does not bear that out.

I remember cold springs in the 70s (when I lived in Sheffield) and this is born out by your graph - over 20 years below the mean with a couple of exceptions. I remember that in the 70s early winter was typically mild, and a white Easter was more likely than a white Christmas!