2018/09/13

First Frost & First Snow: September 12, 2018

Just a quick post today, to commemorate September 12th as the first frost and first snow of the summer/fall/winter of 2018.

First Frost

The average date of the first frost at Blatchford is September 24th, and so the 12th is about 2 weeks early. When we look at standard deviations and the risk of frost, after September 10th is when there's a 10% risk of frost, and we had just crossed that mark.

Other recent years with early fall frosts were 2014 on the 11th, and 2007 on the 13th. But for 2015-2017 the first frost waited until October 4th, 6th and 2nd respectively.

At the International Airport the average first frost is September 10th, so this was basically right on time. The International isn't shown on this chart, but we'd looked at it and a lot of other details in:



The Frost-Free Season

That means that the total length of the frost-free season in 2018 was 135 days. That's a bit below the average of 140 days, but longer than recent years like 2014 at 123, 2010 at 131, and 2009 at 132.


First Snow

With September 12th as the first snow, that also makes this 3 years in-a-row - 2016, 2017 & 2018 - in which the International has recorded snow in September. The last time that happened was 1983-1985. 2014 also had September snow, which means this has been 4-years-out-of-5, and the last time that happened was back in the early 1970s.

Realistically though, lasting snow is still at least a month away, and probably more.  The earliest lasting snow recorded at the airport was October 16, in 2004. More typically it will wait until the end of October, or the first few weeks of November.

We took a detailed look at first & lasting snow last year in: First and Lasting Snowfalls


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