TEMPERATURES

August 2023 was another historically hot month in the Portland Metro, not only was it the warmest August, with a Mean Temperature of 75.4° at the Portland Airport, but it was the warmest month of all-time, beating the previous record of 75.1° set in August 2022, with the data archive going back to Nov. 1940 (see detailed data for Portland’s official stations at the end of this post). For the longer-term downtown Portland weather station (Mean Temperature archive back to 1871), currently at KGW-TV, it was the 3rd-warmest August and all-time month. 

Here in Happy Valley, the August Mean Temperature of 71.5° ranks as #2 warmest August (behind 71.8° in 2017) and fourth-warmest of all months (#1 being 71.9° in July 2015). The Average Minimum Temperature of 59.7° was the all-time warmest month, surpassing the previous warmest of 59.1° set in August 2022. This month’s Average Maximum Temperature was 83.3° ranks as the #2 warmest August out of the last 10. 

This month had 6 days with Daily Maximum Temperatures of ≥90°, with 2 of these reaching ≥100° (14th & 16th). The hottest period this month occurred from the 13th-16th when Maxima reached 99.1°, 104.1° (month’s Maximum and all-time warmest August temperature), 97.8°, and 99.6°. On the cooler side, there were 4 Maxima of ≤75°, all occurring during the final 9 days of the month, the coolest being the 63.5° on the 31st, the only day with significant rain – this 63.5° was not only the coolest Max. Temp. of the month but also the coolest August Max. Temp. of the last 10 Augusts. The Max. Heat Index hit 110° (14th) while temperatures were ≥100° for more than 4 hours.

Minimum Temperatures ranged from a low of 49.7° on the 19th to a high of 69.3° on the 15th & 16th. Only 19 days fell to ≤60°, equaling the number of days in August 2022. Just a single day reached ≤50° with the 49.7° on the 19th. Splitting the month in two, the Average Max./Min./Mean Temperatures were quite different, with the second half being significantly cooler, especially on the Maximum side: 1st-16th, 86.8°/61.0°/73.9°; 17th-31st, 79.6°/58.3°/68.9°. The Maximum Diurnal range was 37.6° (99.1°/61.5°) on the 13th, the least being just 5.5° (63.5°/58.0°) on the very wet 31st.

 

HAPPY VALLEY AUGUST 2023 STATISTICS:

 

HAPPY VALLEY MONTHLY WEATHER FORM: AUGUST 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 AUGUST 2023:

Data Periods of Record for the three official Portland stations:

• Portland International Airport (PDX) – Period of Record: since 10/1940.
• Portland – Downtown (KGW-TV) – Period of Record: since 1/1871.
• Portland – National Weather Service Forecast Office (WFO) – Period of Record: since 2/1996.

 

For AUGUST 2023, the 3 official Portland stations were well-above Normal temperature-wise, precipitation about Normal:

 

 

AUGUST 2023 Precipitation (and Departures, Percentages of Normal for the 30-Year Period 1991-2020):

• PDX Airport: 0.62″ (+0.08″, 114.8%)
• Downtown: 0.59” (+0.05”, 109.3%)
• WFO: 0.49″ (-0.13″, 79.0%)

 

THE AUGUST 2023 MONTHLY TEMPERATURE & PRECIPITATION RECORDS SET:

Portland International Airport (PDX): 

• High Daily Maximum: 108° (14th), 103°  (15th & 16th)
• High Daily Minimum: 69° (5th), 67° (6th, tie), 67° (7th), 68° (14th, tie), 73° (15th), 71° (16th), 68° (25th), 64° (26th)
• High Daily Mean: 84.5° (13th), 88.0° (14th), 88.0° (15th), 87.0° (16th), 81.0° (25th)
• Average Monthly Maximum Temperature: 87.1° ranked #3 warmest August, #5 for any month (tied with 8/2017)
• Average Monthly Minimum Temperature: 63.6° ranked #1 warmest for August and for any month
• Average Monthly Mean Temperature: 75.4° ranked #1 warmest for August and for any month 
• Summer Average Maximum Temperature: 83.7° ranked #3 all-time warmest 
• Summer Average Minimum Temperature: 59.8° ranked #3 all-time warmest
• Summer Average Mean Temperature: 71.7° ranked #3 all-time warmest  
• Highest August All-Time Daily Maximum Temperature: 108° (14th), previous record was 107° (8/10/1981 & 8/8/1981)
• All-Time Number of Consecutive Days with Minimum Temperatures ≥60°: 19, ending on 8/18/2023 (tied with 1998, ending on 8/1)
• Daily Precipitation: 0.55″ (31st)

 

Portland – Downtown (KGW-TV): Data was finally reported as of 9/8/2023. The daily and monthly records are being researched and added at this time.

• High Daily Maximum: 104° (14th)
• High Daily Minimum: 73° (14th), 74° (15th), 70° (16th)
• High Daily Mean: 88.5° (14th), 87.5 ° (15th), 86.0° (16th)
• Average Monthly Maximum Temperature: 84.2° ranked #7 warmest August and #6 for any month
• Average Monthly Minimum Temperature: 62.2° ranked #1 warmest August and #1 for any month
• Average Monthly Mean Temperature: 73.2° ranked as #3 warmest August and #3 for any month (both just 0.1° behind #2’s 73.3° in 8/2022)
• More extremes still being researched. 

 

Portland – National Weather Service Forecast Office (WFO): 

• High Daily Maximum: 102° (13th), 107° (14th), 101° (15th), 103° (16th)
• Low Daily Maximum: 69° (28th)
• High Daily Minimum: 65° (5th), 64° (7th), 68° (15th), 69° (16th)
• Average Monthly Maximum Temperature: 85.8° ranked #3 warmest August and #6 for any month
• Average Monthly Minimum Temperature: 60.9° ranked #1 warmest August and #1 for any month
• Average Monthly Mean Temperature: 73.3° ranked as #2 warmest August and #3 for any month (tied with 2018)
• Summer Average Maximum Temperature: 82.7° ranked #3 all-time warmest 
• Summer Average Minimum Temperature: 57.3° ranked #6 all-time warmest
• Summer Average Mean Temperature: 70.0° ranked #3 all-time warmest (tied with 2022)
• Highest August All-Time Daily Maximum Temperature: 107° (14th), previous record was 104° (8/3/2017 & 8/2/2017)
• All-Time Number of Consecutive Days with Minimum Temperatures ≥60°: 15, ending on 8/17/2023 (previous record was 10, ending on 3 different dates: 8/3/2022, 7/3/2015, and 8/20/2014)
• Daily Precipitation: 0.45″ (31st)