Early September heatwave on the way


In this morning’s weather discussion on the Kitsap Sun’s homepage, I discussed the possibility for a pretty major heatwave to take place midweek this week. Not that I advocate playing hooky, but…well, if there was anytime to take a few days off of work or school to enjoy summer’s last hoorah, it would be Wednesday and Thursday of this week. Heck, let’s just add in Friday for good measure 😉

A building thermal trough from the south is getting ready to pump in some heat for Western Washington from the already heat-opressed regions of the Desert Southwest (read more about thermal trough’s here). This will spell a series of sunny and hot early September days with clear nights. In fact, we could have some of the warmest temperature readings of the season over the next few days.

Here is a temperature forecast brought to you by the University of Washington’s Atmospheric Sciences department. The following map shows Wednesday’s high temperatures. As you can see, most of Kitsap County is well into the 80s, if not near 90 degrees for some spots:

Screen Shot 2013-09-10 at 10.29.25 AM

And here’s a peek into Friday, which shows us “plummeting” to near 80 degrees:

Screen Shot 2013-09-10 at 10.32.08 AM

Reaching 80 degrees in September has actually become quite the norm around here in recent years, but reaching 90 is nothing short of a late summer miracle. Here are some years we got close to or exceeded 90 degrees in the past decade:

  • September 11th, 2011: 86 degrees
  • September 22nd, 2009: 93 degrees (I should also add we dipped down to a jaw-dropping 46 degrees that night!)
  • September 10th, 11th 2007: 84 degrees
  • September 3rd, 2006: 95 degrees (also an overnight low of 46!)
  • September 28th, 2003: 86 degrees

Another interesting note: We have managed to exceed 90 degrees twice in the past decade, while every year before that going back to the early 90s we hardly ever got close. To compliment that, particularly warm Septembers have almost always correlated with a sharply colder and wetter fall season. Why? I’m not sure, but the correlation is there!

How about breaking records? That’s tough to say around here, since record keeping is spotty in the Kitsap area, but the records I have indicate today (September 10th) holds a record high of 84 degrees set back in 2007, September 11th’s record is 86 degrees set back in 2011, and September 12th’s record is 82 set back in 2002. I think we have a decent shot at breaking all of those records!

So yes, it’s going to get exceedingly warm around these parts over the next couple of days. But fear not, cool weather lovers! Our natural air conditioning kicks in by the weekend into early next week, bringing temperatures back to the low to mid 70s. Weather conditions beyond that get a little fuzzy to pin down, but it does appear this is summer’s last gasp.


Matthew Leach

Forecasting Kitsap

Questions? Comments? Photos? E-mail me at: forecastingkitsap@live.com