Weather Blog

1971 still the champ for cold Junes

1971 still the champ for cold Junes
June 1971 can breathe easier now, as it will remain all alone atop its perch as the coldest June ever.

Not that many are complaining, but the 83 degree reading last Friday and quasi-warm weekend, combined with a second warm stretch expected later this week, means this June's average high temperature is already now over the record coldest (62.78 versus 1971's record of 62.73) and highs through the end of the month are expected to be well above 62 each day.

In fact, 82 might be too cold for expected high temperatures as we get hints of a building moderately warm stretch for the end of the week. So since cool, June weather will be but a memory as we sizzle a bit later this week, here is one last chilly stat, courtesy of resident weather-stat head Jason Phelps:

Going back to 1894, Seattle has had nine years where it didn't reach 85 at all during the entire year:  1909, 1917 (the worst "barbecue index" champ), 1918, 1921, 1929, 1950, 1954, 1957, and 1976. Note that we haven't done that in 32 years -- with the previous longest "drought" being 21 years.

He also found that when records were kept in Downtown Seattle from the 1890s to 1945, the average hottest temperature recorded for the year was 89 degrees. Once it moved to Sea-Tac Airport in 1945, it was about 90 degrees through the 40s and 50s, but these days the average is about 93-94 degrees.

There could be several factors in play. One could be a signature of global warming, but part of it could be the urban heating effect -- as Seattle and the surrounding metro areas grow and we replace vegetation with asphalt and concrete, that absorbs heat better.  That also explains why overnight lows in the city have trended higher in recent years -- Seattle does a better job of saving the daytime heat.

Speaking of daytime heat, to touch a little more on what we teased earlier -- it does look like Seattle might get their first extended warm period starting Friday and lasting through the weekend.

Actually, anytime you hear of a heat wave in California, that's usually a good sign that we'll warm up in a week or two as it makes the pool of hot air down there easier to tap into.

But so far, long range models are not advertising a major heat wave or anything around here.  Just a run-of-the-mill thermal trough that will bring in our warm, east wind.

The trough itself looks about moderate in strength, and the air mass rates about a 5 or 6 on the "hot" scale of 1-10 for how hot it can get around here. Initial data suggests highs in Seattle in the low-mid 80s from Friday through Monday -- maybe a few upper 80s on Saturday -- so we'll be upping the high temperatures on our evening forecast for the end of the week.  It will be interesting to see with these two warm stretches where this June ends up on the all-time chilly chart.  Could be that we even fall out of the Top 5. But those who were here won't need fancy statistics to remember this (almost) historic June :)