Excessive Heat in Oregon, June 25 to 30, 2021

Name: Excessive Heat in Oregon, June 25 to 30, 2021
Start: 2021-06-25T00:00
End: 2021-06-30T23:59
Location: Oregon

June 25 to 30, 2021 · NWS PDT · 13 events in 13 counties and zones

A strong upper level ridge of high pressure and a surface thermal trough brought several days of record high temperatures across the PacNW, with many locations in the lower and higher elevations experiencing extreme heat risk during this event. The multiple days of extreme heat risk has been attributed to several fatalities across the region.

Where it happened

Every event with a place to put it; 13 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 2
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 13

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS PDT wrote it up.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Pendleton, OR wrote its last area forecast discussion before the first event at Jun 24, 9:46 PM PST, 2 hours 14 minutes earlier.

Area forecast discussion, Jun 24, 9:46 PM PST, 2 hours 14 minutes before

Area Forecast Discussion
National Weather Service Pendleton OR
1046 PM PDT Thu Jun 24 2021

Updated Aviation Discussion

SHORT TERM...Strong upper ridge will remain over the Pacific
northwest the next few days with northerly flow aloft and hot
temperatures. Satellite indicates mid and high level clouds
moving over the ridge and across the forecast area tonight into
Friday. Then mainly clear skies Fri night into Saturday. As for
temperatures 850mb and thickness values indicate about 4 degrees
of warming for Friday and another 5 degrees Saturday. This will
put highs at 90-103 Fri and 95-108 Sat. Thermal trough will bring
north-northeast surface winds 10-15 mph each day. 94

PREV DISCUSSION... /issued 453 PM PDT Thu Jun 24 2021/

SHORT TERM...
Tonight through Saturday night...High pressure has begun to build
into the region and will be the dominant weather feature for the
foreseeable future. This subsidence associated with this high
will yield increasingly hot temperatures through the period. Highs
on Friday will be warmer than today, but not unbearable for this
time of year, with most locations in the 90s and the Basin likely
reaching triple digits. The real heat begins on Saturday. The
excessive heat watch was upgraded to an excessive heat warning
earlier for all areas beginning Friday afternoon.

A strong upper-level ridge will continue to build over the PacNW.
This will result in very hot daytime high temperatures around 10
degrees hotter than Friday. Lower-elevation areas of the CWA such
as the Lower Columbia Basin and eastern Columbia River Gorge will
likely fall within the 105-110 range. The heat, combined with a
northeasterly breeze during the afternoon, will exacerbate fire
weather concerns. Central Oregon will be slightly cooler with
highs in the upper 90s.

Remember...stay hydrated...stay inside and in air conditioned
facilities if possible, stay out of the sun and check on relatives
and neighbors. Wear lightweight and loose fitting clothing. If you
must be outside, take frequent breaks and try to find some time in
the shade.

LONG TERM...
Sunday through Thursday...There is good agreement through the
extended period of an upper level ridge of high pressure centered
over the PacNW through at least next Thursday, with uncertainty in
the progression of a weak closed upper low off the coast of
northern CA and OR.

Hot temperatures and dry conditions will continue to headline
through the extended period as an upper level ridge of high
pressure and surface thermal trough sit over the region. Ensemble
and deterministic guidance are currently showing Monday and
Tuesday as the peak days for the heat. Afternoon temperatures are
expected to be 100-115 for most of the lowland areas, with
mountain locations in the 90s and possible breaking 100 degrees
either day. Looking through ensemble spreads, ECWMF, GFS, and even
NBM members are showing high confidence in basin locations
breaking 110 degrees each afternoon starting Sunday through at
least Wednesday. Morning lows will not bring much relief from the
heat either, as ensemble members are consistent in showing morning
lows in the mid 60s to mid 70s. As for heat risk, much of the
guidance puts the region well above the 95th percentile for risk.
This prolonged period of hot and dry conditions with little
overnight relief will greatly raise the potential for heat related
illnesses as well as negatively impact drought conditions across
the region. Otherwise, the extended period will see locally breezy
easterly winds Sunday and Monday as thermal trough axis setups
west of the Cascades.

The other point of interest through the extended period is a
cutoff low off the coast of northern CA and OR Sunday and Monday
that models have been consistent in showing the past several runs.
With it's current track, the low will not have much impact on the
region, however, if it trends closer to the coastline, the
southern OR Cascade region will see a southerly flow develop with
possible increasing instability. Right now, confidence is low that
this cutoff low may make a closer approach, however, any
increasing instability in the Cascades could pose increased risk
for fire behavior. Lawhorn/82

AVIATION...06Z TAFS...A few mid-level clouds are noted at the this
evening around 15000 feet. Broken to scattered periods of these
could be possible as an area of of mid-level moisture moves in
from British Columbia, but broken clouds at high elevations
should return by the day tomorrow, followed by skies clearing
tomorrow by the evening hours. Winds become more northerly across
the region into the day, though remain generally in the 5-10kt
range at ground level. Goatley/87

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  61  97  65 102 /   0   0   0   0
ALW  68  97  70 106 /   0   0   0   0
PSC  63 101  67 107 /   0   0   0   0
YKM  61  98  66 106 /   0   0   0   0
HRI  67 100  64 107 /   0   0   0   0
ELN  63  96  65 104 /   0   0   0   0
RDM  52  96  58  99 /   0   0   0   0
LGD  57  92  58  96 /   0   0   0   0
GCD  57  92  62  99 /   0   0   0   0
DLS  69 100  69 108 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Excessive Heat Warning from 2 PM Friday to 8 PM PDT Thursday for
     ORZ041-044-049-050-502-503-505>511.

WA...Excessive Heat Warning from 2 PM Friday to 8 PM PDT Thursday for
     WAZ024-026>030-520-521.

&&

SHORT TERM...94
LONG TERM....82
AVIATION...87

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

13 excessive heat. Local standard time, as filed.

Excessive Heat, Foothills of the Northern Blue Mountains of Oregon

When: June 25, 12:00 AM PST to June 30, 11:59 PM PST
Where: Foothills of the Northern Blue Mountains of Oregon forecast zone
Reported by: ASOS
Coordinates: 45.592, -118.737 (the zone’s center; the record gives no point)

Calculated heat risk values at the Pendleton WFO recorded consecutive days between June 27th through June 30th of temperatures that met or exceeded excessive heat warning criteria. Calculated heat risk at the Milton Freewater, OR GHCN station recorded consecutive days between June 25th through July 1st of temperatures that met or exceeded excessive heat warning criteria. The highest recorded temperature in the zone was 117 degrees recorded at the KPDT ASOS site on June 29th.

Excessive Heat, Eastern Columbia River Gorge

When: June 25, 12:00 AM PST to June 29, 11:59 PM PST
Where: Eastern Columbia River Gorge forecast zone
Reported by: ASOS
Coordinates: 45.314, -120.689 (the zone’s center; the record gives no point)

Calculated heat risk values at the KDLS ASOS recorded consecutive days between June 25th through June 29th of temperatures that met or exceeded excessive heat warning criteria. Several locations including the KDLS ASOS recorded consecutive days over 110 degrees through the period, with KDLS recording 118 degrees on June 28th.

Excessive Heat, North Central Oregon

When: June 26, 12:00 AM PST to June 29, 12:00 AM PST
Where: North Central Oregon forecast zone
Reported by: Official NWS Observations
Coordinates: 45.283, -120.928 (the zone’s center; the record gives no point)

Calculated heat risk values at a GHCN in Moro, OR recorded several consecutive days between June 26th and June 29th of temperatures that met or exceeded excessive heat warning criteria. Many locations, including those of RAWS and NWS sites recorded multiple days of highs at or over 105 degrees.

Excessive Heat, Ochoco-John Day Highlands

When: June 26, 12:00 AM PST to June 30, 11:59 PM PST
Where: Ochoco-John Day Highlands forecast zone
Reported by: RAWS
Coordinates: 44.381, -120.359 (the zone’s center; the record gives no point)

Many RAWS stations across the zone recorded consecutive maximum daily high temperatures over 95 degrees through the period, while the Haystack RAWS had recorded consecutive days of daily highs over 105 degrees.

Excessive Heat, John Day Basin

When: June 26, 12:00 AM PST to June 30, 11:59 PM PST
Where: John Day Basin forecast zone
Reported by: Official NWS Observations
Coordinates: 44.885, -120.192 (the zone’s center; the record gives no point)

Calculated heat risk values at a GHCN at the site 35 WNW of John Day, OR recorded consecutive days between June 26th through June 29th of temperatures that met or exceeded excessive heat warning criteria. Several locations including a USCRN and CWOP stations recorded consecutive daily highs over 105 degrees, with a CWOP station recording consecutive daily highs at or above 110 degrees.

Excessive Heat, Southern Blue Mountains

When: June 26, 12:00 AM PST to June 30, 11:59 PM PST
Where: Southern Blue Mountains forecast zone
Reported by: RAWS
Coordinates: 45.153, -119.262 (the zone’s center; the record gives no point)

Nearly all RAWS stations across the zone recorded consecutive daily high temperatures over 95 degrees through the period, with several sites recording consecutive days of daily high temperatures over 105 degrees.

Excessive Heat, Lower Columbia Basin

When: June 26, 12:00 AM PST to June 30, 11:59 PM PST
Where: Lower Columbia Basin forecast zone
Reported by: ASOS
Coordinates: 45.506, -119.160 (the zone’s center; the record gives no point)

Calculated heat risk values at the KHRI ASOS recorded consecutive days between June 27th through June 30th of temperatures that met or exceeded excessive heat warning criteria. Calculated heat risk values at the Boardman, OR GHCN station recorded consecutive days between June 26th through July 1st of temperatures that met or exceeded excessive heat warning criteria. Many CWOP stations and the ASOS at KHRI recorded consecutive days of temperatures over 110, while the highest recorded temperature was 118 at KHRI on June 29th.

Excessive Heat, Foothills of the Southern Blue Mountains of Oregon

When: June 26, 12:00 AM PST to June 30, 11:59 PM PST
Where: Foothills of the Southern Blue Mountains of Oregon forecast zone
Reported by: Unknown
Coordinates: 45.174, -119.941 (the zone’s center; the record gives no point)

Calculated heat risk values at a GHCN site in Heppner, OR recorded consecutive days between June 27th through June 30th of temperatures that met or exceeded excessive heat warning criteria.

Excessive Heat, East Slopes of the Oregon Cascades

When: June 26, 1:00 PM PST to June 30, 11:59 PM PST
Where: East Slopes of the Oregon Cascades forecast zone
Reported by: Official NWS Observations
Coordinates: 44.568, -121.190 (the zone’s center; the record gives no point)

Many RAWS stations across the zone recorded consecutive maximum daily high temperatures over 95 degrees through the period, with several RAWS sites recording multiple consecutive days of maximum daily high temperatures over 105 degrees.

Excessive Heat, Central Oregon

When: June 27, 12:00 AM PST to June 30, 11:59 PM PST
Where: Central Oregon forecast zone
Deaths: 2 direct, 0 indirect
Reported by: Official NWS Observations
Coordinates: 44.229, -120.920 (the zone’s center; the record gives no point)

Calculated heat risk values at a GHCN in Bend, OR and at the Redmond Airport recorded several consecutive days between June 27th through June 30th of temperatures that met or exceeded excessive heat warning criteria. Many locations, including those of RAWS and NWS sites recorded multiple days of daily high temperatures over 105 degrees. In the Bend, OR area on June 28th, two fatalities reported were attributed to the excessive heat.

Excessive Heat, Wallowa County

When: June 27, 12:00 AM PST to June 30, 11:59 PM PST
Where: Wallowa County forecast zone
Reported by: AWOS
Coordinates: 45.445, -117.595 (the zone’s center; the record gives no point)

The Joseph State Airport AWOS and the Roberts Butte RAWS recorded consecutive daily high temperatures over 100 degrees through the period.

Excessive Heat, Northern Blue Mountains

When: June 27, 12:00 AM PST to June 30, 11:59 PM PST
Where: Northern Blue Mountains forecast zone
Reported by: ASOS
Coordinates: 45.494, -117.976 (the zone’s center; the record gives no point)

The Meacham ASOS, the Eden and Black Mtn. Ridge RAWS recorded consecutive daily high temperatures over 95 degrees through the period, with the Meacham ASOS and the Eden RAWS sites recorded consecutive days over 100 degrees.

Excessive Heat, Grand Ronde Valley

When: June 29, 12:00 AM PST to June 30, 11:59 PM PST
Where: Grand Ronde Valley forecast zone
Reported by: Official NWS Observations
Coordinates: 45.310, -118.009 (the zone’s center; the record gives no point)

Calculated heat risk values at a GHCN in La Grande, OR recorded consecutive days between June 29th through July 2nd of temperatures that met or exceeded excessive heat warning criteria. The ASOS at the La Grande/Union County Airport recorded consecutive days of daily highs at or above 105 degrees.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Excessive Heat, Central Oregon	2021-06-28			Outside/Open Areas	Direct
Excessive Heat, Central Oregon	2021-06-28			Outside/Open Areas	Direct

What these are

Excessive Heat: Heat at or above the local excessive heat warning criteria, or heat that caused deaths.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Oregon in 2021 Every state in 2021 This day in weather history Warnings in Oregon, June 2021

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 969141, 969154, 968860, 968867, 968870, 969133, 969144, 969147, 968864, 968866, 969138, 969140, 968872.