It’s the middle of summer, so what better time to bring up snowfall! Are there really decadal cycles in snowfall across the northeastern U.S.? I’ve been looking at this trend for years determining that there are what I call “high” and “low” snow cycles. I’ve finally decided to “show” it with data. I have compiled seasonal snowfall charts from 4 long-term climate stations across the northeast, Philadelphia, New York City (Central Park), Boston, and Blue Hill Observatory in Milton, MA.

Looking at the chart for Philadelphia (KPHL) using the yellow 10-year running mean line, we can make out the cycles, albeit a bit subtle at times.

We can see some distinct peaks and valleys, generally lasting on average about 10 years each (some are shorter, some are longer). Looking at the years starting in about 2015/16, we see a rather sharp decrease in the 10-year running average seasonal snowfall. We are clearly in a “low” cycle, and have been for about 10-11 years so far.

Now let’s take a look at New York City – Central Park (KNYC).

We can see the same overall trend as do with KPHL, well at least since 1890. KNYC’s record goes back 20 years further than KPHL, but if we compare them from 1890 onward, we see a very similar trend in the 10 year running mean (yellow line). Again, since about 2015-16, we have been in an overall downward cycle (2015 itself notwithstanding)

Boston (KBOS) again shows a similar trend, however we have to be careful with Boston’s snowfall as some seasons since about 1996 have had poor measuring practices, thus many seasons have totals that are skewed low. Regardless of this fact, the 10-year running average still shows the overall high/low cycles.

Blue Hill Observatory’s (BHO) data is much more consistent as the location and methods in measuring haven’t changed since 1885. The chart here continues to show the same overall trend in the 10-year running averages (blue line).

So, in conclusion, there is definitely a high/low cycle in snowfall that seems to last on a decadal timescale. We are currently well within a low cycle, and based on persistence should begin to climb out of it by the end of this current decade. This would imply that the 2030s should return to seeing more normal to above snowfall seasons than dud seasons overall. Granted 4 stations across the region is rather small sample size, but it still shows a rather distinct trend. At any rate, let’s see how this works out!

-MFD