HAPPY VALLEY, OREGON WEATHER: MAY 2020
TEMPERATURES
May 2020 averaged around two degrees above normal for this area but varied widely through the month. The first 3 days were chilly, with Maximums holding in the 50s to low 60s, warming to the upper 70s (8th) to low 80s (9th-10th), the first readings ≥80° since 9/6/2019. Maximums quickly cooled again, remaining mostly below normal until near month’s end (only 55.0° on the 20th, the month’s chilliest reading) when a quick heat spell invaded our area from the south, causing the temperature to soar to 92.7° on the 28th, the only temperature this month to reach 90°, in fact the only reading to reach 85°. This was the first ≥90° temperature since 8/28/2019. May ended on a chilly note as rain moved in for the final two days, holding Maxs in the low-to-mid 60s.
As for Minimum Temperatures, as usual, they didn’t vary as much as the Maximums. The month began cool, with 39.5° on the 4th being the month’s coldest reading, followed by the warmest period, with mid-50s on the 8th and low 60s on the 9th-10th, the only Mins. ≥60° this month. The Maximum Diurnal range was 35.5° (84.3°/48.8°) on the 27th, the least being just 5.0° (56.7°/51.7°) on the 18th, the wettest day of the month.
Maximums ≤32°: 0
PRECIPITATION
It was an unusually wet month, far exceeding the previous five Mays as 4.41″ was measured, besting the monthly total of 3.03″ in 2017. The 30-year average (1981-2010) for this location is 3.26″ (according to Oregon State University’s PRISM model found at: http://www.prism.oregonstate.edu), which results in this month being 35% above the Normal amount. Measurable rain fell on 21 days so there were, obviously, no prolonged periods of dry weather, the longest such stretch being just 4 days (8th-11th). The middle third of the month totaled 2.16″ (49% of the May total), with the first and last thirds receiving 1.06″ and 1.19″ (24% and 27%), respectively. The greatest 24-hour amount was the 0.54″ that fell from the morning of the 18th into the early morning hours of the 19th.
≥0.25″: 8
≥0.50″: 3
≥1.00″: 0
MISCELLANEOUS
Sky Cover: 5 Clear, 13 Partly Cloudy, and 13 Cloudy days.
Barometric Pressure ranged from a maximum of 30.48″ (6th) to a minimum of 29.68″ (12th & 17th).
Relative Humidity peaked at 99% (11 different days) and reached a Minimum of 25% (28th).
Dew Point went from a maximum of 64° (29th) to a minimum of 29° (7th).
Wind averaged 0.2 MPH and the Maximum Gust reached 15 MPH (7th).
HAPPY VALLEY MONTHLY WEATHER FORM: MAY 2020
Cover Photo: Rhododendron & Bumble Bee, 5/24/2020.