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

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

We have had 5 straight well below normal days in fact this is the 2nd chilliest start to August in my 22 years of records here in East Nantmeal behind only the start of August 2021. We should be closer to normal temperatures today before we fall back a few degrees below normal for Thursday through Saturday before we should start a nice warmup into the middle of next week. Cloudy with maybe some sprinkles today - otherwise sunny and dry for most of the next week.

We have had 5 straight well below normal days in fact this is the 2nd chilliest start to August in my 22 years of records here in East Nantmeal behind only the start of August 2021. We should be closer to normal temperatures today before we fall back a few degrees below normal for Thursday through Saturday before we should start a nice warmup into the middle of next week. Cloudy with maybe some sprinkles today - otherwise sunny and dry for most of the next week.

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.

Updated 90 degree days this summer through today along with average 90+ days in a typical entire summer. So still time to get to normal at some locations. Of note PHL Airport has recorded 30 such days and Reading Airport with 21 days.

Updated 90 degree days this summer through today along with average 90+ days in a typical entire summer. So still time to get to normal at some locations. Of note PHL Airport has recorded 30 such days and Reading Airport with 21 days.

For sure a little from around 53.6 to about 54.3 at KRDG....of course we are in a warming cycle for the last 30 years....but why is PHL going up so much faster?

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!

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. Oh that PHL UHI pulling away!

Following our first 4 days with well below normal temperatures we rebound today to near normal. It will be a bit cloudier both today and tomorrow. Clearer skies return on Thursday through the weekend with temperatures near to a little below normal levels for early August. Next rain chances look like next Monday at the earliest.

Following our first 4 days with well below normal temperatures we rebound today to near normal. It will be a bit cloudier both today and tomorrow. Clearer skies return on Thursday through the weekend with temperatures near to a little below normal levels for early August. Next rain chances look like next Monday at the earliest.

Another long term climate site - West Chester 2NW vs PHL Airport 1941 - 2016 West Chester cooling while PHL of course off to the warming races

Except it does not!! Clearly PHL Airport see below is warming much faster due to the UHI at the airport

The first 3 days of August have featured temperatures nearly 10 degrees below normal. We see temperatures rebound this PM to near normal with highs in the low to mid 80's. Similar temperatures tomorrow before we turn again a few degrees below normal to close out the work week. Near normal temperatures return next weekend. Rain chances look slight but more clouds and maybe a shower on Wednesday.

The first 3 days of August have featured temperatures nearly 10 degrees below normal. We see temperatures rebound this PM to near normal with highs in the low to mid 80's. Similar temperatures tomorrow before we turn again a few degrees below normal to close out the work week. Near normal temperatures return next weekend. Rain chances look slight but more clouds and maybe a shower on Wednesday.

For those searching for UHI adjustments at the PHL Airport....we found them - but in 26 of the last 29 years NCEI has actually made warming adjustments....green is raw.

They have both been in the data set for at least the last couple years. Made sense to add as they both were sited at about the same location/elevations just a 1.5 mi W of Elverson on the Chesco border. Helps better even out the mix of higher and lower elevation stations.

See above added Morgantown and Hopewell....the stations analyzed are now only 34 feet higher on average than in the 1970's

To put a further fine point on this - Charlie's statement above is incorrect. The average station elevation has not increased by 100ft. Below by decade is the average elevation of Chester County stations. They have clearly not changed much at all!

Yawn...Actually the relative weighting toward more lower elevation stations from the 1970's thru today has not changed. The actual station trend has been to increasing number of lower elevations stations in the network and a shift toward an increasing number of lower/warmer elevation stations has actually increased significantly since the 2000's.

This morning’s low of 55.7 was the chilliest morning here in East Nantmeal since the 55.1 reading back on June 4th. The lowest temperature around the county this morning was the 52.3 at the Warwick Township station. The first 2 days of August have averaged around 10 degrees below normal temperatures. Today will continue the below normal start to the month, but we have a quick 2 day warm up on Monday and Tuesday with temperatures not too far from average in the mid 80’s. Starting Wednesday we chill down a bit again with temperatures finishing out the work week a few degrees below normal. There is no rain at all in the forecast for this week.

This morning’s low of 55.7 was the chilliest morning here in East Nantmeal since the 55.1 reading back on June 4th. The lowest temperature around the county this morning was the 52.3 at the Warwick Township station. The first 2 days of August have averaged around 10 degrees below normal temperatures. Today will continue the below normal start to the month, but we have a quick 2 day warm up on Monday and Tuesday with temperatures not too far from average in the mid 80’s. Starting Wednesday we chill down a bit again with temperatures finishing out the work week a few degrees below normal. There is no rain at all in the forecast for this week.

The PHL Airport recorded 21 days over 90 degrees in July. The average high temperature was 90.5 degrees. Our own little heat island spot at Phoenixville clocked in at a toasty 89.2 average high with 15 such days. The growing disparity between Urban Heat Island stations and more rural stations is best highlighted when looking at the average high temperature comparison looking at the airport since 1970 when the heat island problems began in earnest. Comparing there vs. The Phoenixville Cooperative data vs. All other Chester County average high temperatures since 1970. While Phoenixville (purple line) has shown warming during our current warm climate cycle they are now clearly being surpassed by the PHL Airport (red line). The rest of Chester County (blue line) has warmed much slower than both PHL and Phoenixville.