An Excessive Heat Warning continues into this weekend for areas east of the Cascades,
including Hood River and all of central Oregon, where triple digit heat will continue and in
some cities, the worst of the heat is yet to arrive.
Here is the final list of records from western Oregon and southwestern Washington:
New all-time record high temperature:
Portland (PDX): 116 degrees - records at various sites date back to 1874
Salem: 117 degrees
Troutdale: 116 degrees
Vancouver: 115 degrees
McMinnville: 114 degrees
Hillsboro: 114 degrees
Kelso: 110 degrees
Astoria: 101 degrees (tied all-time record)
Corvallis: 110 degrees
Eugene: 111 degrees
Hood River: 109 degrees
Note that The Dalles through Monday evening was the hot spot in Oregon, setting an all-time high record for the city
of 118 degrees. The record may be broken on this Monday or Tuesday. The hottest temperature all time for Oregon
is 119 degrees, set back in 1898 in Pendleton and Prineville. The record could fall this week.
Other records for Portland include the warmest all-time overnight or low temperature at PDX of 75 degrees set Sunday morning. The old record was 74 in July of 2009. Prior to this heat wave, Portland’s (PDX) all time record high was 107 degrees, reached in July of 1965 and twice in August of 1981.
Portland (PDX) broke 7 consecutive daily records, staring with a high-low temperature record 65 degrees last Friday, June 25th and ending with Monday’s high of 116 degrees. It is possible that this afternoon, June 29th will tie the daily record high of 97 degrees in Portland.
As advertised, Saturday, Sunday and Monday was the most historic heat wave on record in terms of the extreme heat. The weather pattern itself was not unusual, but simply a classic strong upper level high pressure ridge, centered over the Northwest. What was unprecedented (in recorded history) was the strength of the pressure ridge. The air mass supported surface temperatures some 10 degrees hotter than Portland had ever seen and we now know, the air mass produced. It would only take a slightly warmer set-up in the future to produce the first ever 120 degree Fahrenheit temperatures in the Willamette Valley. Not saying 120 degree temps will happen anytime soon for Salem or Portland and hoping the current records hold for decades to come.
The Excessive Heat Warning issued by the National Weather Service (NWS) for Saturday
through Monday will likely produce the season's first triple digit heat.
The period of 90 degree or higher temperatures starting Friday and possibly continuing through
Monday July 5th is on track to be historic for several reasons:
1) The all-time hottest June temperature at PDX of 102° will likely be broken.
2) Portland's all-time hottest temperature on record for any time of year may be tied
or broken. The record of 107 degrees has been reached three times over the years. Sunday's high temperature has a chance to reach or surpass the record last reached in August of 1981.
3) The length of the expected heat wave may produce a total of 10 June days reaching 90 degrees or hotter. The current record total for 90° days in June is 9 days back in 2015. The streak into July may reach a total of 11 consecutive days, which would also break a record.
4) Many daily temperature records are likely to fall, including daytime highs and records
for warm overnight lows. The current forecast shows low temperatures in the 70s Sunday and Monday mornings and both would set records. In fact, the all-time warmest low temperature at PDX in June is 71 degrees. I expect the record to fall.
It is important to note that an unprecedented June heat wave does not guarantee a record hot summer. Meaning the upcoming hot spell could be the worst this summer season offers up.
You may have heard that the National Weather Service Summer Outlook for June - August calls for above normal temperatures across all of the Northwest and below normal rainfall. The news is not good as we come off of Portland's record dry spring, picking up just 27% of normal rainfall for March - May or 2.52" in comparison to the climate average of 9.37 inches.
Individual weather models show above normal rainfall in August, which could be an indicator of convective activity, meaning lightning, but we can hope for the best. (The 2nd map shows Canadian model August rainfall - green color being above normal.) The core of summer heat this summer is likely to be centered over the upper Rockies and upper midwest, as seen on the 3rd map in the darker tan color from the Canadian July outlook.