No end in sight to this year’s growing season

Posted Tuesday, October 12, 2021

By now everyone probably realizes that cooler temperatures and less humid weather are headed our way at the end of this week. A strong cold front will finally bring an end to our extended summer.

But, this much-advertised cooler weather won’t necessarily mean the end of our growing season. Temperatures will become cooler – but not real cold. Nighttime temperatures in the Valley will likely remain well above freezing behind our weekend cold front. Below is a plot of forecast temperatures from the GFS Ensemble model through October 27:

According to current projections, nighttime lows in the Valley are likely to get pretty chilly – maybe in the low-40s at times. That’s way too warm for frost and of course, not anywhere near freezing. However, we have to keep in mind that this is only a model idea. Sometimes the models have it right and sometimes they don’t.

If the projections ARE right, That could mean our growing season potentially extending into early November. For those unfamiliar, the annual growing season is the period between the last freeze (32°) in the spring and the first freeze of fall.

The average length of the growing season in our area is 168 days. We’re currently at 152 days for 2021. The longest growing season we’ve had was 198 days. That one occurred in 2019. I only looked back 24 years, though.

The average date for the first freeze of fall in our area is October 18.

Growing Seasons calculated at Harry Clever Field in Now Philadelphia going back 24 years.

As you can see in the records above, ALL of our first freezes in the fall have occurred in October over the last 24 years. The latest freeze occurred in 2014 on the 31st.

No worries, though. The growing season will eventually come to an end at some point. We can’t avoid winter after all.



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