ChescoWx

I split our weather database almost down the middle to compare how our climate here in Chester County has changed compared to the first 66 years of climate data (1893-1959) vs. the last 67 years of data (1960-2025). Of note 7 months have trended cooler - 3 have trended warmer and 2 have remained about the same. Overall, on an annual basis we have trended cooler by 0.2 degrees during the latest period of record.

I split our weather database almost down the middle to compare how our climate here in Chester County has changed compared to the first 66 years of climate data (1893-1959) vs. the last 67 years of data (1960-2025). Of note 7 months have trended cooler - 3 have trended warmer and 2 have remained about the same. Overall, on an annual basis we have trended cooler by 0.2 degrees during the latest period of record.

I split our weather database almost down the middle to compare how our climate here in Chester County has changed compared to the first 66 years of climate data (1893-1959) vs. the last 67 years of data (1960-2025). Of note 7 months have trended cooler - 3 have trended warmer and 2 have remained about the same. Overall, on an annual basis we have trended cooler by 0.2 degrees during the latest period of record.

The correct answer remains as always - climate change!! LOL!!

If looking to stay away from that summer like heat from this week....the ensemble models keep us below normal into May.

A much chillier day underway with showers across the area. We have already picked up 0.12" here in East Nantmeal with a little more on the way with shower chances continuing till about noon. Today’s temperatures will run about 20 degrees colder than normal with highs struggling to escape the 40's. Unseasonable cold tomorrow with highs again in the 40's. A freeze watch starts tomorrow night at midnight with lows by Tuesday morning in the low to mid 20's in the colder valley locations. We start a slow warming trend that lasts through the week with temperatures by Thursday near 70 degrees.

A much chillier day underway with showers across the area. We have already picked up 0.12" here in East Nantmeal with a little more on the way with shower chances continuing till about noon. Today’s temperatures will run about 20 degrees colder than normal with highs struggling to escape the 40's. Unseasonable cold tomorrow with highs again in the 40's. A freeze watch starts tomorrow night at midnight with lows by Tuesday morning in the low to mid 20's in the colder valley locations. We start a slow warming trend that lasts through the week with temperatures by Thursday near 70 degrees.

For those folks down the shore - the chilly ocean water temps working their unfortunate magic for folks down in Sea Isle City NJ for Girl's weekend....highs in SIC have not moved much from around 50 degrees all day. The beauty of coastal climes in the Northeast US in spring! Can hardly see through the fog and marine shank!

For those folks down the shore - the chilly ocean water temps working their unfortunate magic for folks down in Sea Isle City NJ for Girl's weekend....highs in SIC have not moved much from around 50 degrees all day. The beauty of coastal climes in the Northeast US in spring! Can hardly see through the fog and marine shank!

Today will be our last above normal day though Wednesday. Today’s temperature will approach 70 degrees especially the further west you go. Tomorrow temperatures will struggle to escape the lower 50's. We should see some showers along the cold front during the morning tomorrow with between 0.10" to 0.40" of rain possible. By Monday temperatures in the higher spots will likely stay in the 40's with a freeze likely Monday night into Tuesday morning. We start to moderate with temperatures back to several degrees above normal in the low 70's by Friday.

Today will be our last above normal day though Wednesday. Today’s temperature will approach 70 degrees especially the further west you go. Tomorrow temperatures will struggle to escape the lower 50's. We should see some showers along the cold front during the morning tomorrow with between 0.10" to 0.40" of rain possible. By Monday temperatures in the higher spots will likely stay in the 40's with a freeze likely Monday night into Tuesday morning. We start to moderate with temperatures back to several degrees above normal in the low 70's by Friday.

The Devault DEOS station recorded a high of 90.7 yesterday this is the first 90 degree reading at any County station so far this year. None of the other stations reached 90 but upper 80's were common across the valley locations. Today should be 10 to 12 degrees cooler with highs in the mid to upper 70's. This is still 10+ degrees above normal levels. We chill well below normal by Sunday with highs remaining in the low to mid 50's with shower chances increasing. A freeze remains a possibility by Tuesday morning.

The Devault DEOS station recorded a high of 90.7 yesterday this is the first 90 degree reading at any County station so far this year. None of the other stations reached 90 but upper 80's were common across the valley locations. Today should be 10 to 12 degrees cooler with highs in the mid to upper 70's. This is still 10+ degrees above normal levels. We chill well below normal by Sunday with highs remaining in the low to mid 50's with shower chances increasing. A freeze remains a possibility by Tuesday morning.

Warmest day of the year 87.5 for the high in East Nantmeal

As per the World Meteorological Organization (WMO) Current climate normals are calculated using the past 3 complete decades and recalculated every 10 years. So, I went back and calculated what was normal for the last 10 climate normal periods specifically for Chester County PA. The below show what the climate normals were for the 10 years following each calculation with the earliest being 1901-1930 normals and the latest being our current climate normal period of 1991-2020. Averages in red are the warmest and blue the coolest across those periods. Of note our warmest climate normal period was 1931-1960 and our coolest period was 1961-1990.