When would you say winter starts in Bellingham? Have you ever noticed how the astronomical seasons seem to be reasonably accurate for spring, fall, and summer, but they seem to be way off for winter? Like, every year it rolls around where someone says, “Hey, it’s officially fall (or spring or summer) today,” and it usually isn’t that surprising. But, when it comes to winter, it’s almost laughable. Like wow- glad the calendar finally caught up with the times!

So when does winter start in Bellingham? Well, I suppose the first question is: What counts as winter? 

It’s rarely sunny in Bellingham in the winter. Bellingham is arguably the cloudiest city in the United States. It is likely worse than the Seattle-Tacoma metro, which was rated the gloomiest metro area in the United States, according to BestPlaces.net. If you are easily claustrophobic, Bellingham may not be the city for you.

It’s often rainy in Bellingham, but not really. It’s like Safeway is turning on their vegetable mister every half-hour all day, every day. It’s not flattering, but I often describe Bellingham rain as spit because it starts and stops in little biting shocks of liquid all day.

When it comes to wind and temperature, there isn’t much to write home about. The best way to describe Bellingham’s weather in terms of temperature is- it’s rarely cold, but it’s never warm. Every so often, the winds can get pretty wild. In October and November, we are known for some pretty strong wind storms from the southwest. December through February, the strongest winds are often from the northeast. That being said, the winds are mild most of the time.

The truth is, the Pacific Northwest takes about 4 months (March to July) to transition from winter to summer, but it only takes about a month to transition from summer to winter. By the time fall comes, winter is on its heels. But when does this all take place?

I decided to devise a metric and do a little research to identify the first day of winter in the Pacific Northwest. It is entirely subjective, but I believe it accurately encapsulates the characteristics of the beginnings of winter for Bellingham.

Here is my metric for identifying the first day of winter in Bellingham: 

The first day of winter in Bellingham is the first day of the first 7-day stretch that has: 

Temperature: Only 1 day above 60 degrees 

Precipitation: 3 days that measure at least 0.25 inch of rain or 6 days with measurable rainfall. 

Below is an example from 1992 of what I was looking for.

Disclaimer: I am using these criteria for two reasons. First, in short, the reality of Pacific Northwest weather is that upper atmospheric dynamics seem to like to keep the flood gates open once they have been unlatched. Second, once the temperature consistently stays below 60 degrees for a week, it doesn’t really rise back above 60 degrees again until early March. 

I then looked through the Bellingham Airport’s daily weather data from 1990 to 2019 to identify these 7-day stretches and locate the “first day of winter” each year. Below is a table identifying the 7-day stretch in dark blue and first day of that stretch in light blue that met the criteria for each year from 1990 to 2019:

If you are like me, this doesn’t really help you make sense of things. I made this graph and thought it would be exciting and then I was kind of disappointed. But maybe you’re not like me, and you can make all kinds of sense out of this. The most notable observation I can make is this: Weather that is highly characteristic of winter in Bellingham starts well before December 22 (Astronomical start of winter). It appears that mid-October to mid-November is the typical window of time for winter to begin.

From this data I gathered the following:

Average First Day of Winter: October 29

Most Common First Day of Winter: November 3

Median First Day of Winter: October 30

So, it appears that generally speaking, winter in Bellingham starts somewhere around the very end of October or the beginning of November. This is striking because late September is often still very reminiscent of summer, meaning that winter often swoops in within a month. 

You may be wondering, based on these criteria, has winter already started in Bellingham this year, or will it start soon? We actually had a pretty wet week last week, but I would say the temperatures were too warm to call it winter-like. Next week, we will feel the first real chills of winter. Therefore, arguably winter is soon to begin. But the conditions of cool and consistently wet don’t look like they will converge for a week or two. Fun…

For those of you that know me well, you may be shocked that I just wrote a whole blog about winter weather and neglected to make any mention of snow. Rest easy. Jack Frost has some things to say soon…