HAPPY VALLEY, OREGON WEATHER: SEPTEMBER 2020
The big windstorm and subsequent wildfires were the big news this month. Here in Happy Valley, very strong, dry east winds out of the Columbia River Gorge brought many trees and power lines down as gusts reached over 50 MPH for the 3-day period 7th-9th (our power outage lasted for about 30 hours, from early morning on the 7th through late morning on the 8th). Fire evacuations were in effect, with Happy Valley mostly at the lowest Level 1 category, “Be Ready.” The very southern parts of the city were at Level 2, “Be Set” while the highest Level 3, “GO!” was just a short 2 miles from there as the Riverside Fire was approaching from the southeast, reaching parts of the town of Estacada, about 11 miles to the southeast. The smaller Dowty Fire developed even closer, between Estacada and Happy Valley, and was more the cause of our local evacuation concerns. Hazardous, thick smoke covered the area from the 9th into the 18th when winds, which had basically been non-existent during these previous 10 days, finally shifted and began coming from the west; much-need rain also rolled through, accompanied by 45 minutes of nearly continuous thunder, both the wind and rain helping to diminish the smoke, pushing it eastward and out of the region. This alleviated the fire threat and greatly assisted exhausted firefighters.
TEMPERATURES
September averages were above normal this month, especially on the Minimum side. Maximums were about 1.0° above Normal with Minimums about 4.0° above Normal, providing Mean Temperatures about 2.5° above Normal. It was a typical September in that the warmest weather occurred at the beginning and mostly gradually cooled as the month progressed, at least until the last few days. The month’s highest reading was 90.6° on the 3rd, the only day to reach ≥90°, the coolest Maximum occurring on the 25th with just 59.9°. Oddly, the Average Minimum Temperature for September of 56.8° was actually warmer than both July (55.8°) and August (55.6°), the two normally warmer months; the lowest September daily reading of 49.8° was just 0.1° cooler than July’s and 2.0° warmer than August’s daily readings. September’s warmest Minimum was the 64.7° on the 9th, one of five days to remain ≥60°. The month’s highest diurnal range was 32.2° on the 3rd (90.6°/58.4°), the lowest only 4.4° on the chilly 25th (59.9°/55.5°).
Maximums ≤32°: 0
PRECIPITATION
There was not a drop of rain through the first 17 days of September. In fact, there was no measurable rain back to and including August 22nd, this rainless streak totaling 27 days (a trace of rain did fall on August 29th). However, this was not the longest dry streak of this year as a 29-day streak occurred from July 8th-August 5th. These are the 4th and 5th longest dry streaks at this location since it was established on May 10, 2014, the three longest being 56 days (June 17th-August 8th, 2017), 54 days (July 3rd-August 5th, 2018), and 39 days (June 4th-July 12th, 2015). Finally, the first decent rain this month arrived on the 18th, totaling 0.81″, accompanied by thunder in the early morning hours, with an even heavier amount beginning in the afternoon on the 23rd, ending later evening, totaling 1.41″. Though there were only 6 calendar days of measurable rain, the Normal monthly amount of 1.79″ for this location was still exceeded.
≥0.25″: 3
≥0.50″: 2
≥1.00″: 1
MISCELLANEOUS
Sky Cover: 14 Clear, 4 Partly Cloudy, and 12 Cloudy days (most being from the thick wildfire smoke).
Barometric Pressure ranged from a maximum of 30.42″ (27th) to a minimum of 29.77″ (23rd).
Relative Humidity peaked at 100% (19th, 20th, 24th, & 26th) and reached a Minimum of just 16% (8th & 9th).
Dew Point went from a very sticky maximum of 67° (3rd) to a minimum of 26° (8th).
Wind averaged just 0.2 MPH and the Maximum Gust reached just 17 MPH (7th & 8th in a very protected area – gusts were likely above 50 MPH in unprotected areas).
HAPPY VALLEY MONTHLY WEATHER FORM: SEPTEMBER 2020 (Click the date link to access a pdf version of the data).
Cover Photo: Smoky Wildfire Sunset, September 7, 2020.