ChescoWx

Below is a chart splitting the Chester County PA Climate Period between almost down the middle since 1895. We have 64 years climate averages by month from 1895 thru 1959 with a comparison to the most recent average temperatures for the 63 year period from 1960 thru 2023. The top (Grey) includes all 27 Chester County stations (even those introduced with modest relative elevation increases). The next section (Yellow) shows the adjusted NOAA/NCEI Altered Adjusted Data. The bottom (green) only includes the 17 stations at a similar relatively lower elevation. Not surprising across all of the actual data there has been essentially no change in our average annual temperatures over the last 63 years vs. the prior 64 years. The only way we get any warming (+1.2 degrees) at all to appear is to apply the post observation adjustments to the data (as shown in the altered data in yellow). Of most interest overall Januaries have trended colder and Decembers warmer but all other months only show slight variations over the split climate periods of record.

Quite the spread of rain totals since yesterday with the warm frontal passage with much more across Southwest Chester County with around 4.37" at Nottingham Park to as little as 0.15" at Devault in Northeast Chester County. Very humid this morning before a strong cold front enters the County from West to East around the 3pm till 4pm time frame. A beautiful Friday through most of Sunday with pleasant temps with lows in the 50's and highs in the mid 70's give the AC a rest! Chester County Records for today: Highs 102 degrees at Phoenixville (1925) 99 degrees in Coatesville (1899) in Western Chesco / Low 38 degrees at Coatesville (1958) / Rain 4.80" in West Chester (1928)

Quite the spread of rain totals since yesterday with the warm frontal passage with much more across Southwest Chester County with around 4.37" at Nottingham Park to as little as 0.15" at Devault in Northeast Chester County. Very humid this morning before a strong cold front enters the County from West to East around the 3pm till 4pm time frame. A beautiful Friday through most of Sunday with pleasant temps with lows in the 50's and highs in the mid 70's give the AC a rest! Chester County Records for today: Highs 102 degrees at Phoenixville (1925) 99 degrees in Coatesville (1899) in Western Chesco / Low 38 degrees at Coatesville (1958) / Rain 4.80" in West Chester (1928)

Below is an analysis of Spring (April-May) average temperatures here in Chester County PA from 1895 through this year. Of note the actual temperature trends (Blue) show almost no warming at all... while the NOAA Altered Adjusted data (Red) shows as expected some solid warming.

Showers should hold off till late in the day and arrive across the county from SW to NE this evening. Showers tomorrow will end by evening but some spots could see over an inch or more of rain by tomorrow night. Cooler and drier weather arrives for the weekend with falling back below normal with temps no higher than the low to mid 70's. Below normal temps should continue through the first few days of next week. Chester County Records: High 102 degrees at Phoenixville (1925) and in Western Chesco it was the 97 degrees that same day. Low 39 degrees at Coatesville (1947) / Rain 2.39" Coatesville (1970)

Showers should hold off till late in the day and arrive across the county from SW to NE this evening. Showers tomorrow will end by evening but some spots could see over an inch or more of rain by tomorrow night. Cooler and drier weather arrives for the weekend with falling back below normal with temps no higher than the low to mid 70's. Below normal temps should continue through the first few days of next week. Chester County Records: High 102 degrees at Phoenixville (1925) and in Western Chesco it was the 97 degrees that same day. Low 39 degrees at Coatesville (1947) / Rain 2.39" Coatesville (1970)

Why would they be warming at all during our current warming cycle? They are doing very well at continuing to warm the present!

Yep they warmed 20 of the last 23 years vs. actual see below to it would seem to enhance the warming.. Only those in red were cooling adjustments Year Actual NCEI Altered Adj. 2001 74.3 75.3 1.0 2002 76.1 77.1 1.0 2003 73.0 74.1 1.1 2004 72.3 73.1 0.8 2005 76.5 77.4 0.9 2006 75.3 76.2 0.9 2007 74.5 75.4 0.9 2008 74.8 75.4 0.6 2009 72.9 73.9 1.0 2010 76.8 77.4 0.6 2011 75.4 76.8 1.4 2012 75.2 76.9 1.7 2013 74.2 75.5 1.3 2014 73.9 73.1 (0.8) 2015 74.9 75.4 0.5 2016 77.4 78.1 0.7 2017 74.6 74.7 0.1 2018 75.4 76.8 1.4 2019 76.5 76.3 (0.2) 2020 78.0 78.0 0.0 2021 77.1 77.1 (0.0) 2022 76.8 77.3 0.5 2023 74.8 76.3 1.5

Below shows that of course NCEI has warmed 20 of the last 23 summers at MDT....from the actual (blue)to the altered (red)average temp lines.

Just the facts and not surprising at all during our current warm phase....but still several chilliest summers ever in the same 23 year period. Cyclical climate change FTW!!

At MDT since 1941 a total of 14 of the top 25 summers (June thru August) or 56% occurred before the year 2000 during our current warmer cycle. Of note 4 summers since Y2K finished in the top 25 of chilliest summers - 2009 / 2004/ 2003/ 2000

Today should be the warmest day for the next week with temps reaching the mid 80's in most spots. Shower chances increase later tomorrow into Thursday morning. Sunny with slightly cooler than normal temps to close out the week. Chester County records for today: High 101 degrees at Phoenixville (1925) / Low 39 degrees at Coatesville (1929) / Rain 1.91" at Devault (2003)

Today should be the warmest day for the next week with temps reaching the mid 80's in most spots. Shower chances increase later tomorrow into Thursday morning. Sunny with slightly cooler than normal temps to close out the week. Chester County records for today: High 101 degrees at Phoenixville (1925) / Low 39 degrees at Coatesville (1929) / Rain 1.91" at Devault (2003)

While no total washouts for the upcoming week...most days will include at least a chance at some showers. Best day looks like tomorrow and the wettest period from Wed night into Thursday. Chester County records for today: High: 100 degrees at Phoenixville (1936) and in Western Chesco 98 degrees at Sadsburyville (1919) / Low 33 degrees at Phoenixville (1986) / Rain 2.53" at Chadds Ford (1959)

While no total washouts for the upcoming week...most days will include at least a chance at some showers. Best day looks like tomorrow and the wettest period from Wed night into Thursday. Chester County records for today: High: 100 degrees at Phoenixville (1936) and in Western Chesco 98 degrees at Sadsburyville (1919) / Low 33 degrees at Phoenixville (1986) / Rain 2.53" at Chadds Ford (1959)

Some lower spots in the county again touched the 40's while here in East Nantmeal the low was only 55.7 degrees. Partly sunny today with some shower chances tonight. Best day of the week loos like Tuesday with sun and near 80 degrees. Shower chances ramp up for Wednesday night till Friday AM. Chester County records for today: High 98 degrees at Phoenixville (1918) and 94 degrees in Western Chesco at Sadsburyville (1919) / Low 37 degrees at Coatesville (1927) / Rain 4.00" at Chadds Ford (1946)

Some lower spots in the county again touched the 40's while here in East Nantmeal the low was only 55.7 degrees. Partly sunny today with some shower chances tonight. Best day of the week loos like Tuesday with sun and near 80 degrees. Shower chances ramp up for Wednesday night till Friday AM. Chester County records for today: High 98 degrees at Phoenixville (1918) and 94 degrees in Western Chesco at Sadsburyville (1919) / Low 37 degrees at Coatesville (1927) / Rain 4.00" at Chadds Ford (1946)

Across Chester County PA we finished May with an average temperature across the 27 NWS/MADIS stations of 63.9 degrees this was the 27th warmest May since records began in 1893. The warmest station was of course Phoenixville at 65.6 degrees and the coolest was at Warwick Township at 62.7 degrees. The highest temperature during the month was recorded at West Chester with the 88.7 degrees on the 26th. Our lowest temperature was the 40.1 degrees on the 11th. The greatest monthly rainfall was at West Chester with 3.57" of rain. Below is the long term May actual (blue) climate history since 1895 - compared with the altered adjusted (red) NCEI trend lines. The actual lines show no warming and actually some cooling over history....while the adjusted NCEI figures show some slight warming.

Across Chester County PA we finished May with an average temperature across the 27 NWS/MADIS stations of 63.9 degrees this was the 27th warmest May since records began in 1893. The warmest station was of course Phoenixville at 65.6 degrees and the coolest was at Warwick Township at 62.7 degrees. The highest temperature during the month was recorded at West Chester with the 88.7 degrees on the 26th. Our lowest temperature was the 40.1 degrees on the 11th. The greatest monthly rainfall was at West Chester with 3.57" of rain. Below is the long term May actual (blue) climate history since 1895 - compared with the altered adjusted (red) NCEI trend lines. The actual lines show no warming and actually some cooling over history....while the adjusted NCEI figures show some slight warming.

Across Chester County PA we finished May with an average temperature across the 27 NWS/MADIS stations of 63.9 degrees this was the 27th warmest May since records began in 1893. The warmest station was of course Phoenixville at 65.6 degrees and the coolest was at Warwick Township at 62.7 degrees. The highest temperature during the month was recorded at West Chester with the 88.7 degrees on the 26th. Our lowest temperature was the 40.1 degrees on the 11th. The greatest monthly rainfall was at West Chester with 3.57" of rain. Below is the long term May actual (blue) climate history since 1895 - compared with the altered adjusted (red) NCEI trend lines. The actual lines show no warming and actually some cooling over history....while the adjusted NCEI figures show some slight warming.

Hi Don, All valid data points are meaningful....like this one. That does not of course imply that during our current warmer cycle that likely lower mean highs offset by higher mean lows will show overall warmth.

of course.....with the adjustments applied to arrive at the official altered data.

Interesting data here as we have had a very slow start to the warm season across the entire USA this year. Only 4% of USHCN stations have reached 80°F so far this year, which year-to-date, is fourth lowest on record since 1895 behind 2011, 1995 and 1935, and is about the same was 1924. The peak year was not surprisingly 1934. The top five years are 1934, 1936, 1969, 1939 and 1914. No such years at all in the last 55 years??

Sorry to the climate alarmists on this site.....you won't appreciate this info.....but only 4% of USHCN stations have reached 80°F so far this year, which year-to-date, is fourth lowest on record since 1895 behind 2011, 1995 and 1935, and is about the same was 1924. The peak year was not surprisingly 1934. The top five years are 1934, 1936, 1969, 1939 and 1914.

Today is the last day of May and this month will be the 6th straight month to end with above normal temperatures. Our last below normal month was last November when we were 1.2 degrees below normal. Our great weather looks to continue through tomorrow before some rain chances by Sunday PM. Chester County records for today: High 96 degrees at West Chester (1987) / Record low was just last year at Warwick Township at 36.3 degrees / Rain 5.34" in West Chester (1908)