TEMPERATURES

May 2023’s temperatures began mostly hovering around seasonal Normals, though two days of Maximum Temperatures remained in the 50s, with 58.6° on the 1st and the month’s lowest Max. of 55.2° on the 4th. Minimum Temperatures during this time were persistently in the 40s from the 1st-11th. By the 12th of the month, unusual heat for the season enveloped the area, bringing several days of records of both high Maximum and high Minimum temperatures. Maximums peaked in the mid-to-upper 80s from the 11th-15th, with ≥80° extending from the 11th-19th. Minimum Temperatures during this period remained ≥50° from the 12th-20th, with ≥60° on the 14th & 15th. The Min. Temp. of 67.5° on the 14th is the warmest ever in May at this location over the last 10 months of May at this location. Once this heat departed, Maxs mostly remained in the 60s to mid 70s, except a brief period of low 80s on the 25th & 26th. Min. Temps. cooled nicely to the 40s from the 21st-31st, except for low-to-mid 50s on the 26th & 27th.

Overall, there were 10 days with Maximum Temperatures reaching ≥80°, and 5 of these being ≥85°. On the other side, there were 14 days remaining ≤70°, and 9 of these ≤65°. For Minimum Temperatures, 29 of the 31 days remained ≤60°, 20 of these were ≤50°, and 6 being ≤45°.

Demonstrating the mid-month warmth by splitting the month into thirds, the Max/Min/Mean Temperatures were thus: 1st-10th: 65.0°/46.7°/55.8°; 11th-20th: 83.6°/56.4°/70.0°; 21st-31st: 70.8°/47.8°/59.3°.

The Maximum Diurnal Range was 34.0° on the 12th (84.5°/50.5°), the least being 7.2° on the rainy 4th (55.2°/48.0°).

 

HAPPY VALLEY MAY 2023 STATISTICS:

 

HAPPY VALLEY MONTHLY WEATHER FORM: MAY 2023 (click the month to access a pdf of the form).

 

 

For the three official Portland National Weather Service weather stations, here is Temperature and Precipitation data for each location for MAY 2023:

 

The 3 official Portland stations were significantly Above Normal temperature-wise, precipitation being well-below Normal:

 

 

May 2023 Precipitation (Departures, Percentages from Normal for the 30-Year Period 1991-2020):

• PDX Airport: 0.91″ (-1.60″, 36.3%)
• Downtown: 1.20″ (-1.38″, 46.5%)
• WFO: 0.96″ (-1.80″, 34.8%)

 

THE MAY 2023 MONTHLY TEMPERATURE RECORDS SET:

Portland International Airport (PDX): 

•   High Maximums: 90° (5/12), 93° (5/13), 92° (5/14)
•   High Minimums: 57° (5/13), 62° (5/14), 61° (5/15), 60° (5/18), 58° (5/20)
•   High Means: 72.0° (5/12), 75.0° (5/13), 77.0° (5/14), 76.5° (5/15), 72.0° (5/18), 70.0° (5/19)
•  The Average Maximum Temperature of 75.5° ranked as #2 all-time warmest, behind the 76.6° in 1992
•  The Average Minimum Temperature of 53.1° ranked as #1 all-time warmest, ahead of 52.4° in 2018
•  The Average Mean Temperature of 64.3° ranked as #1 all-time warmest, ahead of 63.1° in 1992

 

Portland – Downtown (KGW-TV): 

•   High Minimums: 63° (5/14), 65° (5/15)
•   High Means: 77.0° (5/15)
•   The Average Maximum Temperature of 73.2° ranked as #10 all-time warmest, the highest being 75.8° in 1992
•   The Average Minimum Temperature of 52.2° ranked as #5 all-time warmest, the highest being 54.0° in 1958
•   The Average Mean Temperature of 62.7° ranked as #5 all-time warmest (tied with 1931), the highest being 64.2° in 1958

 

Portland – National Weather Service Forecast Office (WFO): 

•   High Maximums: 89° (5/12), 94° (5/13), 91° (5/14), 92° (5/15), 82° (5/20), 83° (5/25), 86° (5/26)
•    High Minimums: 59° (5/14), 61° (5/15), 58° (5/18), 56° (5/20)
•   High Means: 70.0° (5/12), 73.5° (5/13), 75.0° (5/14), 76.5° (5/15), 71.0° (5/18), 69.0° (5/20), 67.0° (5/25)
•   The Average Maximum Temperature of 74.9° ranked as #2 all-time warmest, just behind the 75.0° in 1997
•   The Average Minimum Temperature of 51.0° ranked as #3 all-time warmest, behind the 51.5° in 2018 & 2005
•    The Average Mean Temperature of 62.9° ranked as #1 all-time warmest, tied with 1997