ChescoWx

We are off to a 1.6 degree cooler start to 2024 (42.6 degrees) compared to last year across the 15 Chester County reporting sites. However while cooler than last year we are at the 9th warmest first 4 months on record since 1893. The Top 8 warmest are 1998 - 44.24 2023 - 44.22 1990 - 44.0 2012 - 43.7 1913 - 43.1 2017 - 43.1 1949 - 42.8 2002 - 42.8

We are off to a 1.6 degree cooler start to 2024 (42.6 degrees) compared to last year across the 15 Chester County reporting sites. However while cooler than last year we are at the 9th warmest first 4 months on record since 1893. The Top 8 warmest are 1998 - 44.24 2023 - 44.22 1990 - 44.0 2012 - 43.7 1913 - 43.1 2017 - 43.1 1949 - 42.8 2002 - 42.8

High here in East Nantmeal was 84.8 - no Airport or MADIS locales here in Chester County PA have hit 90 today. Highest obs was the 87.8 at KOQN airport in West Chester As always 90's are certainly much tougher to find out here in the Western philly burbs

Here in Chester County PA we finished April with an overall average temperature of 53.8 about 2.0 degrees above the long term 132 year average. The warmest spot was as is usually the case Phoenixville as the lowest observation spot in the county at 54.9 degrees. The coolest was the 53.0 in Warwick Township. Overall this was our 28th warmest April on record across 132 years of observation data. Of note 13 of the top 20 warmest Aprils occurred prior to 1990. While 3 of the coldest Aprils have all occurred just since 2007. Below is a graph analyzing the April temp trends (actual in blue) since 1893. I have also as always overlaid the NCEI adjusted temps (in red). As we can see they again consistently applied chilling adjustments to cool the data for every year over 110 consecutive years from 1895 thru 2005. Of interest since 2005 they have now begun to apply warming adjustments to the actual data in 12 of the last 18 years. The appropriate trend lines reflect the clear impact these post hoc adjustments have made to the warming trend lines.

Here in Chester County PA we finished April with an overall average temperature of 53.8 about 2.0 degrees above the long term 132 year average. The warmest spot was as is usually the case Phoenixville as the lowest observation spot in the county at 54.9 degrees. The coolest was the 53.0 in Warwick Township. Overall this was our 28th warmest April on record across 132 years of observation data. Of note 13 of the top 20 warmest Aprils occurred prior to 1990. While 3 of the coldest Aprils have all occurred just since 2007. Below is a graph analyzing the April temp trends (actual in blue) since 1893. I have also as always overlaid the NCEI adjusted temps (in red). As we can see they again consistently applied chilling adjustments to cool the data for every year over 110 consecutive years from 1895 thru 2005. Of interest since 2005 they have now begun to apply warming adjustments to the actual data in 12 of the last 18 years. The appropriate trend lines reflect the clear impact these post hoc adjustments have made to the warming trend lines.

High up to 82.2 so far here in EN

After yesterday's slight cooling today will see temps pop back up into the 80's. We should see temps trend back to normal and then below starting tomorrow through the weekend. Some higher spots in the county may actually struggle to escape the 50's for high temps both Saturday and Sunday. We will also see some showers around by Sunday. We should warm back to above normal by the middle of next week but should see a solid stretch of cooler than normal temps returning by mid-May. Chester County records for today: High 91 degrees at Coatesville (1899) / Low 28 degrees also at Coatesville (1903) / Rain 1.84" at Chadds Ford (1976)

After yesterday's slight cooling today will see temps pop back up into the 80's. We should see temps trend back to normal and then below starting tomorrow through the weekend. Some higher spots in the county may actually struggle to escape the 50's for high temps both Saturday and Sunday. We will also see some showers around by Sunday. We should warm back to above normal by the middle of next week but should see a solid stretch of cooler than normal temps returning by mid-May. Chester County records for today: High 91 degrees at Coatesville (1899) / Low 28 degrees also at Coatesville (1903) / Rain 1.84" at Chadds Ford (1976)

Charlie if you think that chart above is science....I cannot help you. That is simply the plotted adjustments....cleaned and homogenized are the words you need to be keying in on....

Again there is nothing in there that shows the actual adjustments by month and year and the control rationale that were applied for those actual individual Chester County stations.

So Charlie you say "The southern and eastern sections of the county and/or at low elevation are over-represented". Coatesville is in a valley" So to correct this you adjust the average annual temperature to well below what was recorded at the coolest station of record....that is an interesting approach and will of course dampen all of that pesky 1930's and 1940's actual warming...

Again lots of rehashed verbiage but where exactly is the detailed Chester County PA analysis that documents and supports the local adjustments made?. How exactly did they determine to chill each and every year from 1895 till the 2000's. For example why was the full year Chester County average for 1931 chilled by exactly 2.5 degrees.and 1932 by 2.34 degrees? Was a blanket State or Region general approximate adjustment determined and applied ad hoc to all of the actual observations? We seem to have plenty of country, US and World adjustments noted above but where exactly is the support for the Chester County PA adjustments? Can someone point me in that direction for that kind of detailed local data or is it not available? Thanks!

We have a chance to hit 80 degrees here in East Nantmeal for the first time since last September 9th. If not today for sure tomorrow. Mostly sunny both today and tomorrow before shower chances increase by Tuesday PM. Slightly cooler but still above normal temps will close out the work week. Chester County Records for today: High 92 degrees in Phoenixville (1915) / Low 26 degrees at Coatesville (1946) / Rain 2.00" at Devault (1952)

We have a chance to hit 80 degrees here in East Nantmeal for the first time since last September 9th. If not today for sure tomorrow. Mostly sunny both today and tomorrow before shower chances increase by Tuesday PM. Slightly cooler but still above normal temps will close out the work week. Chester County Records for today: High 92 degrees in Phoenixville (1915) / Low 26 degrees at Coatesville (1946) / Rain 2.00" at Devault (1952)

Well again Charlie tell us which stations are as you call them the "warmer parts of the county that were over-represented? they are in fact the only stations we have!! So how the heck are they over represented?? Below are in fact all of the available Chester County PA Stations during that time of greatest post hoc adjustments. While we had less stations we still have at least 4 NWS coop stations represented in the actual data. You will notice yet again that in 21 of these 23 years the NCEI Average temperatures was adjusted downward to below any and all stations in the county. The red numbers and line in the graph show the post hoc adjusted NCEI adjusted County average. Unsurprisingly Coatesville being the furthest NW station and with a bit more elevation ran coolest in most but not all years - but why then take the entire county down below even the coldest station during that time?

Then show us which "high quality" stations besides all of the NOAA stations that I am using are in the above NOAA Chester County temperature data you are showing? Can you please list out the actual stations used? Whichever stations you find they are certainly already included in my actual Chester County data set and analytics.

Below shows the consistent pattern of post hoc adjustments we have seen before. With strong NCEI chilling adjustments in earlier decades and gradual warming adjustments as we move toward the current decade. Actual data is in blue the adjusted Chester County average according to NCEI is in orange. That orange line is certainly scarier looking....

Also of note for the longest climate locales in the Chester County data set - the majority of warmest 3 month periods (March thru May) occurred prior to 1960 Coatesville 7 of the top 10 / Phoenixville 7 of the top 10 / West Chester 6 of the top 10 warmest

Your data is much too small for climate review for Chester County PA. My analytics encompasses all available 24 stations - see the below NWS COOP sites / NWS FAA and DEOS/MADIS sites along with the complete years of record. Also as always the data I show is never adjusted to chill the 1940's!

Today will make it 8 of the last 10 days featuring below normal temperatures. That ends tomorrow as temps soar into the high 70's and then 80's on both Monday and Tuesday! A slight shot at some showers today but a better chance on Tuesday. Temps should remain above normal in the mid 70's for much of the upcoming week. Chester County Records for today: High 95 degrees at Sadsburyville (1915) / Low 26 degrees at Coatesville (1926) / Rain 2.45" at East Nantmeal (2007)

Today will make it 8 of the last 10 days featuring below normal temperatures. That ends tomorrow as temps soar into the high 70's and then 80's on both Monday and Tuesday! A slight shot at some showers today but a better chance on Tuesday. Temps should remain above normal in the mid 70's for much of the upcoming week. Chester County Records for today: High 95 degrees at Sadsburyville (1915) / Low 26 degrees at Coatesville (1926) / Rain 2.45" at East Nantmeal (2007)

Below is an analysis of the average temperature by decade here in Chester County for the months March - April and May since the 1890's. The average temperature over these 132 years of records is 51.5 degrees. So far in the 2020's we are running about 0.5 degrees above the average. The 1940's were not surprisingly the warmest decade.

Below is an analysis of the average temperature by decade here in Chester County for the months March - April and May since the 1890's. The average temperature over these 132 years of records is 51.5 degrees. So far in the 2020's we are running about 0.5 degrees above the average. The 1940's were not surprisingly the warmest decade.

Below is an analysis of the average temperature by decade here in Chester County for the months March - April and May since the 1890's. The average temperature over these 132 years of records is 51.5 degrees. So far in the 2020's we are running about 0.5 degrees above the average. The 1940's were not surprisingly the warmest decade.

Near normal temps today before colder again through Saturday. We may see frost or freezes again by Friday morning. Big warm up on the way by Monday with temps possibly reaching the 80's for the first time in some areas. Chester County records for today: High 91 degrees in West Chester (1960) / Low 26 degrees at Coatesville (1930) / Rain 2.40" in Coatesville (1968)