Decided to take a deep dive in this Chester County stuff for the period 2007-2024. @ChescoWxtook a look at his station compared to the CRN station in Avondale last summer. But I wanted to take a deeper dive. Chescowx.com hadn't updated all of the numbers for 2025, so I limited the analysis to 2007-2024. Here's what I found:
Interesting how much lower the slope of the trendline appears in the official values for Chester County (~7.5F/century) over that timeframe, relative to that of the individual stations. The CRN site shows a warming of about ~12.6F/century.
PHL airport warms at ~12.1F/century. Paul's backyard reflects a warming of ~11.1F/century. His composite average for the county was at ~10.4F/century. But the NCEI official numbers check in much lower for recent warming. Will have to see whether this continues... if this continues for even another half decade or so, I would expect Paul's composite averaging to start producing higher temperature means than NCEI. Recent years, the two estimates have been nearly the same (within ~.1F or so), whereas in the late 2000s, NCEI's value was often about 0.5F higher than Paul's.