Chester County PA - Analytical Battle of Actual vs. Altered Climate Data

[ChescoWx]

Some folks on my FB page asked me to start running some deeper analytic dives into Berks County climate data. Below is KRDG Airport average annual temperatures vs. KPHL Airport and Chester County. 1949 through 2024. KRDG and Chesco not too far off....but oh that PHL UHI pulling away!

[chubbs]

15 hours ago, ChescoWx said:

Some folks on my FB page asked me to start running some deeper analytic dives into Berks County climate data. Below is KRDG Airport average annual temperatures vs. KPHL Airport and Chester County. 1949 through 2024. KRDG and Chesco not too far off....but oh that PHL UHI pulling away!

PHL isn't pulling away though.  You are looking at the regression line, not the data itself. Reading (and Chesco) are warming as fast as the airport at the end of your chart., Note also that there are several years when Reading (and Chesco) is warmer than the Philadelphia Airport. That's a red flag for a data issue of some kind. Those years could have a big effect on the regression line. So what's going on here.

I found two sets of data. COOP data from Xmacis starting in 1999, with the first year of full coverage in 2000; and, ASOS data from IEM which starting in 1943, but with many missing or incomplete years before 1973. Note that I was only able to find info on missing data at IEM with a one month resolution, So there may be some periods with missing data included in this analysis. 

The COOP data starting in 2000 shows a close match between RDG and PHL, with RDG warming faster than PHL, 1.3F/Decade vs 1.0F/Decade

The ASOS data also shows a close match between RDG and PHL, but there is more scatter in the pre-2000 period, perhaps due to missing data. The difference between Reading and Philly is roughly the same in 1943 and 2024.

You are beating a dead horse. There is plenty of high quality data that shows that the Airport is warming at the same rate as Chesco and the entire region. Sure you can find incomplete/inconsistent data or conduct a faulty analysis that says otherwise, but that doesn't negate the findings from the high quality data. You have to look at all the evidence. A piece of evidence that disagrees with consistent results from high quality data is inevitably flawed in some way.  

[ChescoWx]

1 hour ago, chubbs said:

You are beating a dead horse. There is plenty of high quality data that shows that the Airport is warming at the same rate as Chesco and the entire region. Sure you can find incomplete/inconsistent data or conduct a faulty analysis that says otherwise, but that doesn't negate the findings from the high quality data. You have to look at all the evidence. A piece of evidence that disagrees with consistent results from high quality data is inevitably flawed in some way.  

You never disprove the raw data you just say there must be some "kind of data issue" - or hey let's look instead at the COOP data since 2000 ... just moving the goalposts. Sure you can find altered adjusted data or conduct more faulty analysis that says otherwise, but that doesn't negate the findings from the high quality actual raw data.

[ChescoWx]

With July now in the books below is the Average Temperature Trend for Chester County PA from 1893 through 2025...mighty flat!!

[ChescoWx]

Excited to share that my website is about to relaunch with a new modern look (been the same since 1999!!) with all the climate information and analytics you could ever crave for Chester County PA. Stay tuned!

http://www.chescowx.com

 

[ChescoWx]

As a sneak peek into the updated data, charts, analytics and information I will post below the actual raw monthly temperature trends now updated through 2025 for the months of January through July. Of note only less than half of those months shows a warming trend since way back in the 1890's 

 

 

[ChescoWx]

February Average Temperature Trends 

 

[ChescoWx]

March Average Temperature Trends

 

[Stebo]

7 hours ago, chubbs said:

PHL isn't pulling away though.  You are looking at the regression line, not the data itself. Reading (and Chesco) are warming as fast as the airport at the end of your chart., Note also that there are several years when Reading (and Chesco) is warmer than the Philadelphia Airport. That's a red flag for a data issue of some kind. Those years could have a big effect on the regression line. So what's going on here.

I found two sets of data. COOP data from Xmacis starting in 1999, with the first year of full coverage in 2000; and, ASOS data from IEM which starting in 1943, but with many missing or incomplete years before 1973. Note that I was only able to find info on missing data at IEM with a one month resolution, So there may be some periods with missing data included in this analysis. 

The COOP data starting in 2000 shows a close match between RDG and PHL, with RDG warming faster than PHL, 1.3F/Decade vs 1.0F/Decade

The ASOS data also shows a close match between RDG and PHL, but there is more scatter in the pre-2000 period, perhaps due to missing data. The difference between Reading and Philly is roughly the same in 1943 and 2024.

You are beating a dead horse. There is plenty of high quality data that shows that the Airport is warming at the same rate as Chesco and the entire region. Sure you can find incomplete/inconsistent data or conduct a faulty analysis that says otherwise, but that doesn't negate the findings from the high quality data. You have to look at all the evidence. A piece of evidence that disagrees with consistent results from high quality data is inevitably flawed in some way.  

You are correct.

[ChescoWx]

April Average Temperature Trends

 

[ChescoWx]

May Average Temperature Trends

 

[ChescoWx]

June Average Annual Temperature Trends