ChescoWx

Of note Spring of 2026 was the 14th warmest Spring since 1893 - conversely Winter 2025-26 was our 14th coldest! Our weather does have a way of balancing out! Below is our Spring Temperature trends since 1893....only some slight warming evidenced by the data.

Since 1893 we have seen a cooling trend during the month of May here in Chester County PA

Of note here in the philly burbs of Chester County PA Spring of 2026 was the 14th warmest Spring since 1893 - conversely Winter 2025-26 was our 14th coldest! Our weather does have a way of balancing out! Below is our Spring Temperature trends since 1893....only some slight warming is shown.

Of note here in the philly burbs of Chester County PA Spring of 2026 was the 14th warmest Spring since 1893 - conversely Winter 2025-26 was our 14th coldest! Our weather does have a way of balancing out! Below is our Spring Temperature trends since 1893....only some slight warming is shown.

Since 1893 we have seen a cooling trend during the month of May

Since 1893 we have seen a cooling trend during the month of May

Below is the May 2026 Chester County Climate Summary. We finished May with an average temperature of 60.8 degrees across all stations. This was 0.7 degrees below the 1991-2020 average May temperature of 61.5 degrees. This was the 56th coldest May in 134 years of records back to 1893.

Below is the May 2026 Chester County Climate Summary. We finished May with an average temperature of 60.8 degrees across all stations. This was 0.7 degrees below the 1991-2020 average May temperature of 61.5 degrees. This was the 56th coldest May in 134 years of records back to 1893.

Today will be the 11th of the last 13 days with below normal temperatures. Sunny and dry through Saturday. We should finally see some warmer than average temperatures by the end of the week and into the weekend. Rain chances look to increase by Sunday.

Today will be the 11th of the last 13 days with below normal temperatures. Sunny and dry through Saturday. We should finally see some warmer than average temperatures by the end of the week and into the weekend. Rain chances look to increase by Sunday.

I am compiling the final averages but it looks like Chester County will finish around a 1 degree below the 1991-2020 average for the Month of May

But of course during that 1978 to 2025 period Phoenixville 1E is warming at almost a 50% faster rate than the rest of Chester County. The Phoenixville area is about as least representative of the entire county with about 60% of Chesco lying at over 400ft above sea level

Lows this morning were not too far from record cold levels for the final day of May. The lowest was the 38-degree reading at Warwick Township. During our last 37 days we have seen 26 of those days with below normal temperatures here in East Nantmeal. This pattern looks to it will continue through mid-week before we finally see temperatures warming to above normal by the end of the work week. Unfortunately there is no rain in site.

Lows this morning were not too far from record cold levels for the final day of May. The lowest was the 38-degree reading at Warwick Township. During our last 37 days we have seen 26 of those days with below normal temperatures here in East Nantmeal. This pattern looks to it will continue through mid-week before we finally see temperatures warming to above normal by the end of the work week. Unfortunately there is no rain in site.

Maybe an even better example of the Urban Heat Island Problem at PHL Airport is to compare the airport to NWS COOP observations at Octoraro Lake on the SW border of Chester County at about 40 nautical miles due west of the airport. Octoraro Lake is a relative low elevation spot (260 ft asl) and that NWS COOP station is clearly seeing decreasing heat waves while PHL continues to have increasing "heat waves". The only material difference is rural vs UHI