The coastal towns immediately on the shores of the Pacific Ocean have some of the more variable weather conditions around, but as far as forecasting temperatures go in the late spring and early summer? You can pick a high temperature and go with it for weeks on end. You'll rarely be off more than a degree or two.
It's thanks to a persistent ridge of high pressure that typically sits just offshore, pushing an onshore wind over ocean water temperatures that sit in the mid 50s and blows along the coast. Even when it's rainy, foggy, or sunny, that onshore wind is of nearly constant temperature, and thus those along the coast have some of the most consistent high temperature readings around.
But it didn't really hit me just *how* consistent it was until University of Washington research meteorologist Mark Albright pointed out that over the past 26 days in Crescent City, California, the high temperature had been between 58 and 62 degrees. It was even more stable up U.S. 101 a bit in North Bend, Oregon where the last 16 days have had a high of 63 or 61 (with 14 of them being 63).
So I went back and checked a number of coastal towns up and down the Pacific Coast, from Forks to San Diego, and the consistency is quite amazing! I started this chart on May 16 as it was just after a thermal trough passed and conditions returned to normal. (A thermal trough, which brings a hot, offshore east wind to the coast, is about the only way they get really hot. Temperatures reached the 80s and 90s along the coast in mid-May)
* City Codes: UIL-Forks, WA; HQM-Hoquiam, WA; AST-Astoria, OR; OTH-North Bend, OR; CSC-Crescent City, CA; MTR-Monterey, CA; LAX-Los Angeles Airport; SAN-San Diego, CA. Blue numbers: Highs in WA and OR between 60-65°.
No matter where you are on the coast, there is a certain sameness to the day, even in California, where the water and air temperatures are a bit warmer as you'd expect. LAX has had a high between 69 and 74 every day on the chart except for the first two when the thermal trough was still lingering.
San Diego's had a high between 70-74 every day since May 25th, save June 3 when it reached a balmy 76. Monterey, California is among the most expensive cities to live in in the nation but at least its residents don't need to spring for air conditioning. Crescent City routinely stays in the 50s even as the summer solstice approaches.
But before coastal residents just go "I don't need these silly things anymore" and delete all their weather apps from their bookmarks and unfollow me on Twitter, the weather itself varied quite a bit over those days. For example, Crescent City was split nearly 50/50 on sunny days and their typical late spring foggy days. Hoquiam on June 3? Overcast and 61. Hoquiam on June 5? Mostly sunny... and 61.
As someone who lived in two of those cities growing up (Astoria and North Bend) plus Port Angeles (data not available, but it's just as consistently cool) it sure makes for some adaptation when you move away from it. To this day, 80 degrees still feels hot and I'm thankful Seattle doesn't get there *too* often. And, dagnabbit, I have to actually try to figure out a high temperature here.
But if you ever decide you need a spot where you know what the high temperature will be day in and day out this time of year, just go west. Just not too far west.
And still pay attention to us for the actual weather conditions. (Please?)