Fair warning. This post is J.D. ranting about something few people care about: the climate and weather of Portland, Oregon. If that sounds boring to you, you might want to skip this haha.
My buddy Douglas writes one of my favorite newsletters at Substack: Money and Meaning. It’s great stuff, filled with deep insights on what makes humans tick. Today, in a piece entitled “We Are Climate Change”, Douglas wrote:
In the last week, as I’ve been writing this, Portland endured 3 straight days of over 100F. In 2006, when I moved here, the city might get to 90F once or twice a year. Talking to people who grew up here, anything in the mid 80s was a hot day.
All summer, I’ve been seeing similar claims around the interwebs. These claims bug me because I think they’re wrong. These temperatures are not unusual. They’re the norm during Portland summers, and they have been all of my life.
First of all, these claims seem wrong on a gut level. This is my 55th summer in Oregon’s Willamette Valley, and nearly all of them have been hot. Temps over 90 don’t seem rare. And temps in the eighties seem common. I’ve never considered 80 or 85 to be hot. These, to me, are normal summer temperatures.
That’s my view anecdotally, but what do the official records say? Well, the official records back me up.
For 20+ years now, I’ve been a fan of the National Weather Service website. It’s chock full of great statistics and official data. The site’s navigational system is a little wonky, but once you get used to it you can find all sorts of cool info. For Portland (and all of Oregon, I think), the page you want is this one, the climate page.
If you explore the five subsections (NOWData, Observed Weather, Climate Prediction and Variability, Local Data/Records, Climate Resources), you can find just about anything you want to know about the local climate. This is true for Oregon, and I suspect it’s true for all other U.S. states.
If you want it, you can download a comma-delimited file filled with all past recorded data to import into a spreadsheet. But what I find really useful is each city’s climate book. (Here’s the Portland Climate Book.) These publications — and their web-based counterparts — process the data in lots of interesting ways: monthly maximum temps, top 10 warmest days (by month), wettest seasons, first and last snowfall (Portland averages four days per year with measurable snowfall), days with fog, etc.
All of this is to say: There’s a lot of weather data out there for folks who want it. Which brings me back to my complaint. All summer, I’ve been seeing/hearing people claim that Portland never used to get this hot. And that’s just not true.
I used the National Weather Service website to dig up some data. From the NOWData tab on the Portland climate page, I generated some custom reports. Here, for instance, is how I looked up how often Portland reaches temperatures over 100 degrees.
Here are the results of my number-crunching:
- From 1941 to 2022 (which is 82 separate years), Portland experienced a high temperature over 100 degrees in 47 different years — or 57% of all years. We had 101 days reach this high during those 82 years — or just over once per year. (During the two decades from 1977 to 1996, we had 100-degree days in sixteen of those years. Basically, 100-degree days happened almost annually during my formative years.)
- From 1941 to 2022, Portland experienced a high temperature over 90 degrees every year except 1954. We had 1018 days reach this high during those 82 years — about 12.5 times per year.
- From 1941 to 2022, Portland experienced a high temperature over 85 degrees every single year (although 1954 only had one — why was it so cool?). The area averages thirty days over 85 each year. That’s an entire month! If you were to ask me what the average high in Portland is during the summer, I’d tell you 85 because that’s what I’ve always believed.
- From 1941 to 2022, Portland averaged nearly 54 days per year with highs over 80 degrees. Even in the strange, cool year of 1954, the area had ten days over this temp.
Basically, these numbers back up my memories. Portland has always experienced these kinds of temperatures. They’re not new and they’ve never been uncommon.
Now, having said all that, although I disagree with folks on specifics when they claim that Portland didn’t see these temperatures in the past, I agree with their broader overall points. Climate change is occurring. While high temps like this aren’t new for Portland, the frequency with which we reach them is clearly increasing. Most people recognize that climate change is a reality, and for good reason.
(One of my favorite anecdotes from our cross-country RV trip: Kim and I were stranded in Plankinton, South Dakota in July 2015 when our RV engine blew up. We spent ten days hanging out with the local farmers. It was fun! They were a very conservative bunch with stereotypically conservative views — except that every single one of them admitted climate change was happening. They experienced it daily in their crops and harvests.)
There are better ways for people to talk about the changes to Portland’s weather. They start with actual data. Here’s a summary table, for instance, that shows the actual change in the number of days above certain temperatures for the Portland area over 20-year periods.
During the twenty years between 1941 and 1960, Portland averaged about 22 days over 85 degrees each year. In my formative years (from 1977 to 1996), we averaged about 32 days over 85 degrees. And over the most recent 20-year span, we’ve averaged 38 days over 85 degrees. There is a trend here, for sure.
As an area native, it’s not the summer highs that seem unusual to me. No, it’s the summer low temperatures. My memory is that our summer nights used to be much cooler. In recent years, it stays much warmer overnight, which makes sleeping more uncomfortable. This is the change that seems most pronounced to me.
Again, the data backs me up. You can see that we now have 38 nights each year where the temp stays at 60 or more. This is way up from the past.
I’ve wasted a crazy amount of time this afternoon — and written a stupid number of words — because I care about these sorts of claims and statistics. I agree that climate change is happening, but it’s careless to use anecdata to back up claims better supported by actual data. Anecdata harms an argument rather than helping it.
(Sidenote: A bigger pet peeve is the common claim among Oregonians that “it always rains on Independence Day”. Grrrrrr. But I’ve written about this before, so I won’t belabor it now. Let’s just say it’s unusual to have measurable precipitation on July 4th, and it’s rare to have any real rainfall.)
The one thing I wonder about this is that there have been some studies that show that growing urban areas leads to more heat retention–in other words, the asphalt, concrete, and buildings absorb and radiate more heat resulting in hotter days, and more slowly release it resulting in hotter nights. I wonder if a similar analysis done in an area that hasn’t seen much growth would show as much of a change.
I live in Baltimore, and our weather station is near the airport. That area has grown by leaps and bounds over the last 50 years, so I would expect average temperatures to rise based on that alone.
Interesting piece!
My first summer in Corvallis (1972) after growing up in Seattle, I was totally surprised by the 100 degree temperatures in early August. First summer living in Portland (1981), again 100 degree temperatures. Yeah, it’s the hot nights that make it so unbearable. Have to think the 105 and 106 degree heat domes are unusual?