May 2026 Weather In The PNW

[BLI snowman]

1 minute ago, MV_snow said:

I know your climate has changed more than ours, but I’m legit surprised PDX couldn’t even pull this off in June 2022. That was an old school ULL fest up here, but it must’ve been the ridging during the last week (that kicked off a very hot and dry J/A/S) that pushed you over the average.

That was a wet, SW flow driven month with some pretty mild nights. There just wasn't a lot of really cool troughing and yeah, that heat at the end definitely dialed it up a bit.

For WA it was a little cooler, but BLI still ran a +0.6 anomaly that month and SEA which is consistently the coolest station in the region relative to average now still only ran -0.9 on their 1991-2020 average. June 2020 was actually slightly cooler overall for the region.

 

 

[Eugene-5SW]

Eugene closes out May with 0.33" of rain, good for 7th driest all time (130-year POR).

3 of the top 10 driest Mays have been in the last decade.

Average temp of 57.8 is a +1.8 departure, good for 26th warmest all time.

Two more data points in favor of claims that the shoulder seasons are warming and drying.

[StormchaserChuck1]

Just wait until the decadal PDO trends positive. A lot of these recent trends will be accentuated. 

July-Sept has the lowest PDO effect in the NW, of the whole year. 

[TigerWoodsLibido]

2 minutes ago, Eugene-5SW said:

Eugene closes out May with 0.33" of rain, good for 7th driest all time (130-year POR).

3 of the top 10 driest Mays have been in the last decade.

Average temp of 57.8 is a +1.8 departure, good for 26th warmest all time.

Two more data points in favor of claims that the shoulder seasons are warming and drying.

And that's gonna keep moving north...

[BLI snowman]

52 minutes ago, Omegaraptor said:

Fair, May 2024 was a coolish month up north but I do know there was a very sharp N/S gradient across Oregon that May and June. IIRC SLE was also running unusually warm that month.

PDX was running way warmer than any other station in the metro for no apparent reason during late winter and early spring 2025 before it was corrected. The 82°F monthly record set that March at PDX is rather suspect for that reason, but I guess NWS has bigger fish to fry than to investigate that one data point. 

I think the fact that someone is having to go back over two years to cherry pick a month that was very negligibly below average at best like May 2024 was just speaks volumes to where we've been at lately.

Since May 2024, here are Battle Ground's warm season anomalies:

June 2024: +1.1

July 2024: +5.1

August 2024: +1.4

September 2024: +2.7

May 2025: +2.3

June 2025: +2.3

July 2025: +3.5 (missing some days though)

August 2025: +4.5

September 2025: +4.4

May 2026: +4.0 (missing a bit so generously we'll say the last couple days bring that down to +3.5)

 

Framing it as a PDX issue is obvious copium for some.

[Port Angeles Foothiller]

1 hour ago, SeattleSmokeLayerFan said:

Fantastically points out the desensitization to heat by the Tim crowd. Slightly below average temperatures are considered part of a "cold" storm track.

The average is above normal and a big cluster is way above normal. This has been my point for 5 posts now. After June 10th ensembles say warm or lean warm. 

[SeattleSmokeLayerFan]

4 minutes ago, Port Angeles Foothiller said:

The average is above normal and a big cluster is way above normal. This has been my point for 5 posts now. After June 10th ensembles say warm or lean warm. 

Yep, it's only slightly below average for a short period late this coming week. Otherwise it is normal or above normal... 

[Doom Buster]

7 minutes ago, BLI snowman said:

I think the fact that someone is having to go back over two years to cherry pick a month that was very negligibly below average at best like May 2024 was just speaks volumes to where we've been at lately.

Since May 2024, here are Battle Ground's warm season anomalies:

June 2024: +1.1

July 2024: +5.1

August 2024: +1.4

September 2024: +2.7

May 2025: +2.3

June 2025: +2.3

July 2025: +3.5 (missing some days though)

August 2025: +4.5

September 2025: +4.4

May 2026: +4.0 (missing a bit so generously we'll say the last couple days bring that down to +3.5)

 

Framing it as a PDX issue is obvious copium for some.

Your stat was based only off PDX. It's completely fair to point out it doesn't apply anywhere else from SLE north.

You've even admitted yourself that PDX was running as an obvious warm outlier for awhile.

Also the NWS site says PDX was barely below normal in May 2024?

[BLI snowman]

2 minutes ago, SeattleSmokeLayerFan said:

Yep, it's only slightly below average for a short period late this coming week. Otherwise it is normal or above normal... 

Very strong chance that most places are running at least +1 come mid-month. If not a bit warmer.

I guess it's another testament to where we're at when some treat that as "cool". 

[TT-SEA]

17 minutes ago, SeattleSmokeLayerFan said:

Yep, it's only slightly below average for a short period late this coming week. Otherwise it is normal or above normal... 

BS.   Wednesday through Monday will very likely be below normal.   I wish you were right but you aren't.

[Doom Buster]

On 5/1/2026 at 12:42 PM, BLI snowman said:

2015 seems pretty on point right now as far as logs go.  

 

On 5/3/2026 at 11:29 PM, BLI snowman said:

Decent chance we're +10 for the month come the 15th.

Gonna blow away every May record. Just another month in the PNW. 

 

On 5/5/2026 at 8:54 AM, BLI snowman said:

6z GFS absolutely cooks next week. Easily going to be a record warm first half of May. 

6z Euro AIFS had no rain through the 20th and another prolonged round of record heat mid-month. 

Picking up right where you left off last warm season...just keep shooting for the stars!

[SeattleSmokeLayerFan]

2 hours ago, SeattleSmokeLayerFan said:

Don't really see a clear sign of a negatively tilted trough tapping into monsoonal moisture. Probably just wet drizzle if we get any rain. But the Euro shows a pretty solid ridging signal outside of Tim's cherry picked trough frame.

Hmm, some cool, popcorn thunderstorms could be possible on Friday. Not the severe variety though.

[SeattleSmokeLayerFan]

18 minutes ago, TT-SEA said:

BS.   Wednesday through Monday will very likely be below normal.   I wish you were right but you aren't.

5 degrees below avg for a couple days and one day of rain before right back into the 70s and 80s..  

[SeattleSmokeLayerFan]

One thing to note... The average temp should be 70. Not the temp everyday (or according to some here, the lowest the temp should get for things to be "normal"). A couple rainy, cooler days is normal.

A couple days in the 60s won't offset many days in the 70s and 80s, which is what we're looking at. We'll definitely run above average by mid month.

[Deweydog]

517!

[Meatyorologist]

34 minutes ago, TT-SEA said:

BS.   Wednesday through Monday will very likely be below normal.   I wish you were right but you aren't.

..That's what he said?

[Meatyorologist]

3 minutes ago, Deweydog said:

517!

Hopefully we're still allergic to .500

[TT-SEA]

2 minutes ago, Meatyorologist said:

..That's what he said?

He said its warmer than normal forever.   Won't be the case.  

[TT-SEA]

14 minutes ago, SeattleSmokeLayerFan said:

One thing to note... The average temp should be 70. Not the temp everyday (or according to some here, the lowest the temp should get for things to be "normal"). A couple rainy, cooler days is normal.

A couple days in the 60s won't offset many days in the 70s and 80s, which is what we're looking at. We'll definitely run above average by mid month.

Not if we have 5 or 6 marine layer days in a row coming up which is looking more likely.    Struggling into the 60s by mid afternoon... as a few on here constantly complain about the non-existent heat.    First half of June will be at or below normal.  Hopefully second half is warmer than normal.  

[SeattleSmokeLayerFan]

2 hours ago, TT-SEA said:

All I said was I don’t see any extended hot spells.   And I stand by that.  And I am not even sure the first half of June ends up warmer than normal.   Which isn't too far off what that chart is saying.   I understand climo... stop with your whiny drama.

Let's consider the expected departure from average accumulated over time based on the plotted curves.

First, compute the difference between the true AVG (red curve), and the ensemble avg. Then integrate that difference function (find the signed area between the two curves) over time. Then divide by the total time that has passed. As you can see, the value does appear positive.

Now, you might also observe that many ensemble members lean very warm mid month. This means that for many members, the departure is quite a bit higher. Only a few outlier operational runs and related members present a barely average solution.

Of course, at the same time, the increasing entropy suggests a lower confidence later on the time axis (as usual with long range forecasts)... Essentially enabling informational decay and forcing a regression of the ensemble average towards the mean, from what it could potentially be by mid month. The warmer members however seem higher confidence overall based on how they're flexing in those plots and the general climate consensus.

In essence, @Port Angeles Foothiller has a strong point.

[MossMan]

Must be coming! 

[KeyPeninsula_Wx]

Kind of awesome how moving somewhere rural can really affect temp spreads and low temps deep into the season. 70/38 today. Getting into the 30s in mid/late May was pretty much unheard of at my old location in North Tacoma. 

[DareDuck]

1 hour ago, Eugene-5SW said:

Eugene closes out May with 0.33" of rain, good for 7th driest all time (130-year POR).

3 of the top 10 driest Mays have been in the last decade.

Average temp of 57.8 is a +1.8 departure, good for 26th warmest all time.

Two more data points in favor of claims that the shoulder seasons are warming and drying.

Garden variety. 

[MossMan]

Lovely day. 

[Doom Buster]

24 minutes ago, DareDuck said:

Garden variety. 

Are you really that impressed by 26th warmest? 

[Cold Snap]

Low of 39 here this morning.

[Edmonds Husky]

3 hours ago, SeattleSmokeLayerFan said:

If we do care about AI fantasy land, this looks like a treat!

Heat for the whole Lower 48

[MossMan]

6 minutes ago, Edmonds Husky said:

Heat for the whole Lower 48

Phil’s excited! 

[TT-SEA]

42 minutes ago, SeattleSmokeLayerFan said:

Let's consider the expected departure from average accumulated over time based on the plotted curves.

First, compute the difference between the true AVG (red curve), and the ensemble avg. Then integrate that difference function (find the signed area between the two curves) over time. Then divide by the total time that has passed. As you can see, the value does appear positive.

Now, you might also observe that many ensemble members lean very warm mid month. This means that for many members, the departure is quite a bit higher. Only a few outlier operational runs and related members present a barely average solution.

Of course, at the same time, the increasing entropy suggests a lower confidence later on the time axis (as usual with long range forecasts)... Essentially enabling informational decay and forcing a regression of the ensemble average towards the mean, from what it could potentially be by mid month. The warmer members however seem higher confidence overall based on how they're flexing in those plots and the general climate consensus.

In essence, @Port Angeles Foothiller has a strong point.

Its been solidly below normal at SEA since May 15th.   The first half of May was warm... second half has been cool overall.  

[SeattleSmokeLayerFan]

4 minutes ago, TT-SEA said:

Its been solidly below normal at SEA since May 15th.   The first half of May was warm... second half has been cool overall.  

Yet we surged into the 80s in the second half as well. The month ended with a positive departure.

[TT-SEA]

4 minutes ago, SeattleSmokeLayerFan said:

Yet we surged into the 80s in the second half as well. The month ended with a positive departure.

So what... we can easily have a 15-day period that ends up cooler than normal.  My guess is that will be true for June 1-15 as well.

[TT-SEA]

Highs in the 50s with rain next weekend is not going to help the argument for endless heat.  

[SilverFallsAndrew]

1 minute ago, TT-SEA said:

Highs in the 50s with rain next weekend is not going to help the argument for endless heat.

 

If we had an award for out of touch white guy you’d win every time.

[ShawniganLake]

On 5/1/2026 at 11:42 AM, BLI snowman said:

2015 seems pretty on point right now as far as logs go.  

Very close to 2015 for May here. Nanaimo will be a bit warmer and wetter this year.  North Cowichan looking a touch cooler and drier for 2026 vs 2015.  No idea what June will bring but I’d bet on at least a couple solidly warm weeks at some point.  

[TT-SEA]

6 minutes ago, SilverFallsAndrew said:

If we had an award for out of touch white guy you’d win every time.

So that is not a sub-60 day in Seattle?   It definitely is.  And that is nasty for a summer weekend.   And that will be a common sentiment next weekend.

[Deweydog]

Breezy!

[SeattleSmokeLayerFan]

1 minute ago, TT-SEA said:

Wow... what a response.  Classic Andrew.   A majority of people in the world don't have the luxury of worrying about anything being discussed on here at all.   Emotionally melting down because the models take away at snowstorm 5 days out is most definitely a first world phenomenon.

The internet and globalization sort of changed that. If anyone even has access to social media, they can get into these things. There are weather weenies around the world, though it's more common here.

[SilverFallsAndrew]

Today was very pleasant 

[Omegaraptor]

What hotel are you guys gonna book in Pasco for next week’s megatrough?

[ShawniganLake]

Cherries will be ready for picking this week.