ChescoWx

Hey guys, I thought I would start a unique topic (to not take up space in regular obs for those not interested) with some weather factoids related to the philly burbs of Western Chester County PA. Let me know if you have any questions or any analysis you would like to see run with this data set outside of the PHL airport heat island obs. To start off - based on a couple messages on the relationship... if any of following snow seasons to below normal September and October pairings. I did a bit of analysis in the database. With the 1st 10 days of October 2020 averaging over a degree below normal and September 2020 finishing with a below average temperature....if the longer range models are accurate we may indeed have our 1st back to back below normal such months since September/October 2009....that season we finished with 86.6" of snow here in the philly burbs of Western Chester County. Now before you snow weenies get all excited....that was the greatest seasonal snow following below normal Sept/Oct pairings in the local data set analyzed since 1894. Of interest back to back below normal Sept/Oct months have only happened 30 times or 24% of the 127 years of Chester County records. The average Chester County PA snowfall is 35.6" -however, in years following below normal Sept/Oct pairings the average following seasonal snowfall has only averaged 29.2" or 18% below normal. Ranges go from the 1972-73 season when....for the only time in Chester County PA history no measurable seasonal snowfall occurred to the aforementioned 86.6" in the winter of 2009/10. Bad news for snow lovers...70% or 21 of those following winters experienced below normal (35.6") snowfall. In future posts we will look at below normal Sept/Oct/Nov and below normal 3 month averages to the following snow seasons.....maybe there will be hope there.... "Some are weather wise and some are otherwise" Ben Franklin

Still no 30's this year in Western Chester County PA at 685 ft ASL(44.4 this AM)....however down at lake level on Marsh Creek just a couple miles south of here = yet another low in the 30's (36.4) at around 400 ft

Another beautiful fall day across the region with our 6th below normal day of the 8 days so far here in October with highs today in East Nantmeal Twp. in Western Chester County PA of 62.6 and 68.2 down in Sea Isle City NJ along the beaches of South Jersey.

This AM low was 49.5

A new weather tidbit for Western Chester County PA...thanks for all of the emails!! I will try to share more of these unique Western Chester County PA stats more often - also thanks for the feedback on the website http://www.chescowx.com !! I am in the process of upgrading it's appearance and functionality....but my full time job gets in the way of getting this done more quickly. No doubt these updates should help make it more phone friendly... as I know this is a current shortcoming of the current site. Some interesting analysis regarding Octobers by decade below Looking at Octobers by decade since the 1890's - 3 of the last 5 decades are the coldest October decades on record the top 5 coldest are below: 1970's (52.5) / 1980's (52.6) / 1960's (53.3) / 1920's (53.3) / 1990's (53.4) Of the top 5 warmest October decades - 4 of those decades occurred before 1960 1910's (56.7) / 1940's (55.4) / 2010's (55.3) / 1900's (54.9) / 1950's (54.4)

While today's splits both in Western Chester County (60.1/45.1) and down the shore in Sea Isle City NJ (67.5/49.1) were well below normal they were nowhere near as chilly as today just 5 years ago back in 2015...when we stayed in the 40's all day in Chesco with a high of only 49.4 and 0.40" of rain.

Some October climate stats for Western Chester County PA of note since 2010 the month has averaged only 1.3 degrees above the 54.0 degree monthly average. Additionally, 2 of the last 10 Octobers (2011 and 2015) have actually averaged below normal temperatures....while 9 of the last 20 have featured below normal temperatures. Some OCT Climate facts & figures for Western Chester County PA: Highest temp - 94 (10/6/1900 and 10/5/1941) Lowest temp - 17 (10/28/1936) Highest min temp - 73 (10/5/1898) Lowest max temp - 35 (10/30/1925) Average October Temperature - 1894 to 1983 - 54.2 degrees Average October Temperature - 1983 thru 2019 - 54.0 degrees Average date of the 1st Freeze of the HDD season: 1894 to 1982 - 10/14 Since 1983 - 10/23 Earliest Freeze - September 20, 1956 Latest Freeze - November 12, 2005

Beautiful October morning both in Chester County PA and down the shore in Sea Isle City NJ - AM Lows 45.1 in Chesco and 49.1 in SIC

0.16" of rain overnight

Nice autumnal day both here in Western Chester County PA and down the shore in Sea Isle City NJ. quite a bit milder with folks even on the beaches down in Cape May County today.

Here in Western Chester County PA - We finished September with our 1st below normal month temperature wise since the back to back below normal months of April and May 2020. It is also our 1st below normal September since September 2014.

1.08" storm total since last evening

0.55" of rain so far in Western Chesco - our 1st measurable rainfall since September 11th

Today was only our 2nd above normal day here in Western Chester County PA (76.4/51.7) over the last 12 days. I have been telling my local Chester County farmer followers for the last week to expect another well below normal stretch to follow the very brief warm up this weekend as we move into October.....still thinking any freeze concerns and basic end to the growing season over most of Western Chesco which is over 600 ft will wait...till likely the middle of the month. This would still be a bit earlier than our normal 1st freeze for the Western spots in the county which is October 23rd (October 14th for Chesco below 600ft ASL)

Another record daily low max in Western Chester County PA yesterday...the old mark was 63.0 set back in 1991. This morning's low was 40.3

2nd consecutive record low maximum temperature here in Western Chester County PA. Today's high of only 61.2 eclipses the old mark of 63.0 set 29 years ago back in 1991. Down on the barrier islands on the Jersey Shore in Sea Isle City the high was only 63.3. Overall these readings are in line with normal late October readings than mid-September