April Begins Warm & Dry

9:30pm Thursday…

It was another fantastic spring day across the region wasn’t it? Just a few thin high clouds drifting lazily by at times. We made it to 68 in Portland, just a few notches down from the 71 yesterday (March 31st). Salem and Eugene were a bit warmer than yesterday.

March Recap

In my opinion, we’ve had a great start to spring if you like to get outdoors. March was drier than average, with plenty of partly cloudy or sunny days. It was our 7th driest on record at PDX (out of 81), and the 2nd driest during a La Niña winter/spring.

Just as interesting? We’ve now gone through four consecutive years with drier than normal conditions in March. Payback will be a real tough in some future March!

And you can see most of the West has been quite dry this past month

What about temperatures? A bit cooler than average. Not a huge departure, but most of Oregon has been cooler than normal.

Is this unusual? Not really. Looking back at past La Nina springs, there is a very strong signal for cooler than normal across the Pacific Northwest. This is a composite of April-June temperatures for the last 20 La Nina springs. Pretty clear signal isn’t it?

One would think a cool spring would also be wet, but that’s not the case. April through June precipitation from those same 20 springs…well below average.

I don’t mind these springs too much; plenty of sunny or partly cloudy days mixed in with the wet days. Plenty of chilly nights and late frosts (like this year), but a cold/clear night is followed by very strong April/May sunshine too!

Snowpack is still running well ahead of average in northern Oregon; no significant spring melt yet due to the cooler temps. Southern Oregon is not in good shape as of April 1st. Lots of drought issues are likely across the Klamath and Good Lake basins

What’s Ahead?

April is what I call the “greening up” month west of the Cascades. Most deciduous shrubs and trees come alive this month; bare of foliage to start, then flush with fresh leaves & green by April 30th. It’s very dramatic in the woods around my home. Right now the ground is pretty much bare and bright sunshine makes it down to the forest floor. But four weeks from now all the ferns will have popped out of the ground, alder/maple trees will be leafed out. It turns darker and shady in the woods from that point through October.

Portland’s average high temperature rises from 59 > 64, and we typically see 5 days at/above 70 degrees. Last year we made it to 76 degrees late in the month

We have also entered the drier half of the year…just barely. April is slightly drier than October in a typical year as the rainy season slowly winds down

In the short term, we’ve got a dying cold front that brings a few sprinkles to the northern Oregon coastline tomorrow. Then (unfortunately) on Easter a splitting upper-level trough brings another dying front overhead. Lots of clouds that day but not much rain! The fresh 00z GRAF model shows how little rain we expect through Sunday afternoon. If there is no color on this map, that means less than 0.10″ precipitation.

The result? Not much rain and temperatures near normal for this first week of April. And…


Chief Meteorologist Mark Nelsen

46 Responses to April Begins Warm & Dry

  1. W7ENK says:

    Dropped to 26 overnight. Some (recent) Winters have failed to get that cold through the entire season, yet we’re solid into the middle of April now with unarguably more daylight than darkness…

  2. Roland Derksen says:

    Nice sunshine, but breezy cool conditions here this morning. Glancing at the snowline on the mountains to the north of us, I’d estimate the snow level is at 2,500 ASL. It’ll be intresting to see how the warm up this coming week goes.

  3. Joshua Lake Oswego says:

    Another rain goose egg overnight for me. PDX will possibly have less than .10” of rain through the first 20 days of April. That’s after an almost record dry March. That’s after a very dry second half of February. Still haven’t had more than .25” of rain in a day since Valentine’s Day. But hey, it will be warm and sunny next week.

  4. Weatherdan says:

    If this upcoming weather pattern would have come in December or January we would be talking a major Arctic blast. Oh well timing is everything isn’t it. Peace.

  5. Joshua Lake Oswego says:

    Bottomed out at 34.3 in the real dome.

    If you get to keep complaining about the cool nights, I get to keep complaining about the lack of rainfall.

    • 5OClockCharlie says:

      Can I complain about both? I didn’t get any measurable rain, but I had a considerable amount of frost this morning. I live near Stafford, so not too far from you or W7. My confidence in tonight/tomorrow’s rain is also very low.

      • Joshua Lake Oswego says:

        You sure can!

        Yea, looking like another .10” if we’re lucky type of rain. I think I saw a tumbleweed rolling through downtown earlier.

  6. Zach says:

    Are these crazy overnight lows at least in part related to the cold SSTs off the coast right now? That is also weakening the storms and reducing our precip?

  7. W7ENK says:

    Woke up to frosty grass and 30 degrees this morning,
    after an overnight low of 29.

    This is beyond ridiculous.

  8. Jason Hougak says:

    Upper 20s for lows have been the norm so far in the Cascade Foothills.

  9. Zach says:

    The Euro seems to have cooled off a lot next week. I am now seeing PDX temps mainly in the mid 60s?

    • lurkingsince’14 says:

      Still sounds glorious, but Mark still has mid 70s on the 7 day so we’ll see….either way sunshine and warm!

      • Zach says:

        Maybe by next weekend, but not looking like much chance we break 70 Mon-Fri. That trough is digging in too much.

  10. Zach says:

    Wow, Gresham got 0.28″ of rain last night. Other metro areas got completely skunked.

    • Joshua Lake Oswego says:

      Mine was not even measurable.

      • Zach says:

        Huh. Hoping this dry pattern doesn’t cling for too much longer…

      • W7ENK says:

        Every single station on Wunderground in the vicinity of Lake Oswego had measurable rainfall yesterday. I would venture to guess that you did too, only that you chose not to read the measurement. If you’re only going by observation, then of course you didn’t see it, because it all fell between 1:45 and 2:30am.

        Across the river in your rain shadow, I measured 0.06″ yesterday.

        • Joshua Lake Oswego says:

          Dude, I’m telling you it was less than .01”. And, I saw plenty of other stations nearby with nil.

          Regardless of whether it was .00” or .05”, it is meaningless rainfall. We’re in trouble if this pattern doesn’t break soon.

  11. Joshua Lake Oswego says:

    I am already seeing grass go dormant in areas where the soil is thin or loose like near tree roots, driveway medians, and sidewalk edges. I have never seen this happen before May.

    With zero meaningful rain in at least the next 10 days and far warmer than normal temperatures, I would start irrigating your lawns if you want them to stay green.

  12. Roland Derksen says:

    Looks like I’ll see my first good chance to see afternoon temperatures in the 60’s here next week- if the forecast holds. I doubt I’ll see anything above 70 until the end of the month.

  13. Matt in Keizer says:

    “April begins warm and dry”…..now with mid 70’s forecast by early next week…..but not in Alaska!….The whole state on April 6th (except for the S.E. peninsula banana belt) is still an icebox and now in its 7th straight month of below freezing temps. and in many cases still below zero!….Here are todays High/Lows and a few snow depths: Central Area: Fairbanks 15/-24, Bettles 5/-33 & 36″ snow, McGrath 23/-8, North Coast: Barrow 0/-13, West Coast: Kotzebue -4/-18, Nome 17/2, Eastern Area: Northway 18/-19 & 11″ snow, South Coast Area: Anchorage 28/8 & 23″ snow, Kenai 29/2, Valdez 33/21 & 56” snow, and finally the SE peninsula banana belt: Juneau 39/33, Sitka 38/33…… Those are just crazy low temps and high snow depths for April 6th!…..I mean I like snow and cold for a couple of months in the winter but 6-7 months of it….No Thankyou!!….so glad I don’t live their anymore!

  14. Roland Derksen says:

    I think these cool morning temperatures are a result of La Nina- so I’m expecting a cooler than normal spring, and possibly into the first part of summer.

    • Andy says:

      You are very correct…the last couple years we were coming out of a very strong EL Niño globally…now we are turning the corner with ocean temps falling and record cold and snow around the globe…it will only get colder.

  15. W7ENK says:

    I’ve now had as many freezing overnight lows in April as I had last October, and will likely add another one to the pile tonight.

    This is getting ridiculous. I’m ready to plant garden stuff!!

    • 5OClockCharlie says:

      Yeah these frosty mornings are annoying and I see more coming up at least through the weekend. Beyond that is looking nice though, but these crazy swings in temps lately make me nervous about a sneaker frost episode later.

      The one time my vegetable starts are actually taking off and yet I can’t plant them because of frost. Sigh… last year I planted too late, this year apparently too early. Can’t win!

      • W7ENK says:


        I planted 4 each of 8 different kinds of peppers back at the end of January. I’ve already upsized their individual pots once, and they’re going crazy under the lights in my South window. Another week or so (max) and I’ll have to upsize them again, which was supposed to coincide with them going outside, but I don’t trust that it still won’t freeze, which is absurd. I won’t have the room indoors for them at that point.

        And on this subject, it was 32 and frosty again this morning!

        • Joshua Lake Oswego says:

          Move to my neighborhood. I have literally only had frost once this fall/winter/spring outside of the ice event. It has dipped below 32 a handful of times, but briefly and not much below.

        • W7ENK says:

          I’m imagining your neighborhood is full of sagebrush, prickly pear, and joshua trees, but I can’t for the life of me pinpoint it on a map… Is Lake Oswego near Tonopah?

        • Joshua Lake Oswego says:

          They would all probably thrive. The desert can actually get cold at night though. Think more like palm trees, eucalyptus, and birds of paradise.

        • W7ENK says:

          Yes, the desert cools off fast at night. I was going more for the dry aspect of things, actually. It doesn’t sound like you get enough precip for those more tropical things to thrive.

        • Joshua Lake Oswego says:

          We’re all going to be planting cacti if our summer weather pattern continues to begin in March and last through October.

        • W7ENK says:

          It’s 57 degrees under hazy sunshine right now. To refer to this as “Summer” is quite the stretch, especially with the excess number of freezing mornings, which is where this whole conversation began…

        • Joshua Lake Oswego says:

          Summer pattern, not summer temperatures.

  16. Weatherdan says:

    Still cleaning up yard debris from the ice storm. Will be planting my vegetables and flowers in the next week or so. I am so ready for Summer. Peace.

  17. tim says:

    The new crapy gfs 16 is finally catching up to cooler/wetter eruo after days of showing 70s by mid april, only in the richest country in the world can’t have decent weather model, pathetic.

    • Zach says:

      I was thinking that too. The GFS has been on crack the past few days.

    • Joshua Lake Oswego says:

      I’m not seeing anything remotely close to wet in the foreseeable future. .3” – .7” in the next 10 days according to the models. So, in reality, probably less than .3”. I’m going to go out on a limb and say that March 1st – April 15th, 2021 will be the driest on record.

      Our “9 months of rain” is more like 4 these days. March – October is now our dry season.

      • Mike says:

        Last decade in south valley: 1 November, 1 December, 2 Januarys, 2 Februarys have had above normal rainfall. I moved here from AZ 7 years ago and am underwhelmed by the purported rainfall–n
        ot nearly as wet as I had expected…or hoped. Looking like the long term drought is not going away soon, and we may well be headed for another bad fire season.

      • Zach says:

        I think you may be right on that prediction.

        Things could turn on a dime though. Both May and June have potential to be pretty wet months.

  18. Joshua Lake Oswego says:

    Bummer. I hope it comes back.

    On another note, your house is consistently 3-6 degrees cooler than mine overnight. I bottomed out at 37.5. I think it’s because I live on a pretty heavily wooded street. Overnight lows are warmer than almost everybody in the metro area, but our daily high temps are cooler. I will take that trade off. Thank you, trees.

  19. W7ENK says:

    Thank for the update, Mark.

    It will be interesting to see how much longer these freezing overnight temperatures can hold on. Just had my 4th out of the last 5 consecutive frosty mornings with temps at or below freezing. Last night took me by surprise, considering the previous night bottomed out at 38 and it was solid overcast when I went to bed. Woke up to frosty grass and a 32 on my weather station at sunrise. Sadly, I left my starfruit tree outside overnight, and all the brand new leaves fell off of it today. It’s probably dead. I’m not happy. That was a 3+ year experiment, now likely failed.

  20. MasterNate says:


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