Another year complete, a new one just begun, and time for Mark’s annual weather summary.
The big story of 2018 was drought, which is still listed as “severe” as of this writing.
Although 11 of 12 months had below average rainfall, the overall departure – 83% of normal precipitation – is not that extreme. As a recent example, 2013 had a much lower annual rainfall at 24.02″. While 2013 had a relatively wet summer and very dry winter, 2018 had the opposite pattern: 92% of normal rainfall Jan-April and Nov-December and 44% of normal rainfall May-October. We really missed those five inches of expected growing-season rains.
On the plus side, the long dry fall was a boon to seed farmers bringing in late harvests, and a relative paucity of lightning storms, power line failures, and human idiots in our part of western Oregon spared us from a repeat of the 2017 wildfire season despite tinder-dry conditions from July into October.
Aside from the drought, 2018 was somewhat lacking in weather headlines. It was neither exceptionally cold nor exceptionally hot, and the final average temperature – 0.6 degrees above normal – is par for the course or even a bit on the cool side given the current status of global climate change. There were no major windstorms, floods, or other forms of damaging weather that will be remembered into the future.
January was unusually warm, only dropping below freezing on two days and topping out at 63ºF on the 17th, leading buds to pop early and humans to harbor unreasonable expectations of an easy winter and an early spring. Though not exceptionally wet in total, the month had only three days without measurable rainfall.
February continued the warm trend at first with highs around 60, then cooled stepwise after the 8th, first to a week with highs around 50, then to deep winter temperatures with highs around 40 and our coldest morning of the year: 20.6ºF on 2/23. Feb. 22 brought our only snowfall of the year, a short-lived inch or two. Early-blooming trees like apricots and peaches really suffered from this return to cold and wet, setting little if any fruit.
March continued the cool trend, with many highs around 50 and one 70-degree taste of spring on the 12th that would not be equaled for more than a month. Rainfall was near average but sporadic, with a fair number of dry or mostly-dry days.
April was the only month of 2018 with above-normal rainfall – 172% of normal to be exact, and more than would fall in the next six months put together. If a farmer were to pick one month to be wet, April would not be it. Despite the overall drought pattern, fields stayed wet into May and farmers were forced to plant late or to deal with muddy clods. That said, these abundant April showers were essential in helping plants survive the next six months of drought. June-blooming blackberries provided abundant nectar for bees, and established fruit trees set a bumper crop in September thanks in part to this April blessing of moisture.
May marked the transition to warm and dry. Rain fell on only four days, totaling 0.42″ or 21% of normal, but thanks to last month’s rains no one yet lamented a lack of moisture. Mostly it was a month of beautiful days to be alive and outside.
June brought summer about a month early. A tenth of an inch of rain on the 11th would be the last for three months, and the monthly total came to half of normal. After the 11th, we settled into a pattern of peak Oregon weather, with highs mostly in the 70s.
The joy ended in July, also on the 11th, with the arrival of summer heat. From that point through August 22nd, we would have 16 days above 90 degrees and many more in the upper 80s. Those of us who worked outdoors got used to it, with help from typically cool nights and mornings, and were thankful that we were spared the 100s this year.
August was a month of smoke. Though our air quality only measured “unhealthy” on a few days, the high-altitude plumes arriving alternately from the north and south dimmed the sun, reduced the output of my home solar panels, and saved us from reaching 100 degrees on more than one occasion. I wonder if any climate models include the cooling effect of smoke from increased wildfires in their calculations. Wind off of the ocean finally returned on the 23rd with a high of only 66 degrees, and ushered in a return to pleasant summer weather that continued into September.
September had a wet week in the middle, from the 11th to the 16th, which broke our three-month thirst and caused minor headaches for quinoa harvests. That week brought this weather station to 90% of normal rainfall for the month, but the the showers were extremely localized and most areas saw less than half that amount. Warm and dry returned later in the month.
October brought the second and third false starts of fall, with three days of rain on the 3rd-5th and then a moist two weeks beginning on the 23rd. In between was half a month of pure autumn bliss, with drying winds, low humidity, daily temperature swings approaching 50 degrees, and the first light frosts on the 14th and 15th. Total rainfall came to 1.50″, slightly less than half of normal.
Against all odds, November – usually a full month of stormy rain – had two rain-free weeks from the 7th through the 20th. At Wild Garden Seed, we were threshing late-maturing fennel and parsley seed outdoors, marveling at our luck. This was the same stationary high-pressure pattern that brought a devastating wildfire to Paradise, California, but here it only brought frosty mornings (11 days below freezing in a month when it seldom freezes) and sunny, 50-60 degree afternoons. The rainy season finally arrived for good on the day before Thanksgiving, and we were more than ready for it. The long-delayed rains were generous, bringing the monthly total to 5.58″ or within an inch of average.
December brought a bit of everything: a cold snap at the beginning down to 21.8ºF on the 6th, a surprising amount of sunshine in what is often a dreary month, and nearly seven inches of drought-busting rainfall capped by a two-inch atmospheric river on the 18th that stopped just short of causing flooding problems thanks to the not-yet-saturated ground continuing to absorb moisture. Most of the rain fell in the early morning hours on that day, and I will remember it as a bright warm windy day of near-constant rainbows as the sun shone through drops blown from distant clouds. For some reason, the fog always lifted earlier than predicted or failed to materialize this December, and we were thankful for the bright mornings and clear sunsets in between days of rain.