Strong, nearly stationary high pressure led to a week long, intense heat wave with many temperature records broken.
Every event with a place to put it; 5 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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.
The episode as NWS VEF wrote it up.
Strong, nearly stationary high pressure led to a week long, intense heat wave with many temperature records broken.
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 Las Vegas, NV wrote its last area forecast discussion before the first event at Jun 14, 8:50 AM PST, 2 hours 10 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 950 AM PDT Mon Jun 14 2021 .SYNOPSIS...A prolonged and likely record-breaking heatwave capable of significant threats to life and infrastructure will take hold of our region this week and continue into the weekend. Temperatures may begin to decrease early next week but should remain well above average. && .UPDATE...Forecast in good shape today and no updates are planned this morning. Temperatures have continued their upward trend and averaging 2 to 4 degrees higher than they were at this time yesterday. The excessive heat warning goes into effect at many locations, including the Las Vegas Valley momentarily, at 10 am PDT this morning. && .SHORT TERM...Today through Tuesday. The stage is set for an extended period of excessive heat as a strong Four Corners High slowly expands and eventually works its way more directly over our region. Westward expansion of the high will be limited today and Tuesday by a broad trough along the West Coast that will gradually lift inland with its base brushing across northern California and northwest Nevada Tuesday. This setup will continue to produce enhanced southwest winds especially across Inyo County and south central Nevada this afternoon with gusts between 30 and 40 mph. The main impact will be very high to extreme wildfire danger for these areas extending southward to the Spring Mountains and Sheep Range. Winds will remain elevated over Esmeralda, central Nye and Lincoln counties Tuesday as the trough lifts away to the north for continued very high wildfire danger for those areas. Temperatures will climb 2-3 degrees each day today and Tuesday across the region. The Excessive Heat Warning will go into effect beginning at 10 AM this morning and remains in effect until Saturday evening. It is worth noting that the Four Corners High will pull mid and high level moisture up from central Mexico which will bring us some scattered cloud cover with bases above 15 kft MSL. It probably won't provide much relief from the heat and may actually trap heat overnight and increase lows Tuesday night for some areas. .LONG TERM...Wednesday through Sunday. The big story during the extended period will continue to be the upcoming long-duration heatwave that will grip the Desert Southwest. Area-wide heat risk, or the potential for people to experience heat related impacts, will reach "high" or "very high" by Wednesday and persist through at least Saturday. These levels of heat risk mean that much or all of the population, including Las Vegas, will be at substantial risk for heat related illnesses and impacts. How is this risk calculated and why the attention on heat in the desert in June? We will approach the discussion today answering those questions. Consideration 1: High temperatures. High temperatures are enough to be their own headline, with records expected to be broken across much of the area beginning Tuesday and through possibly into the weekend. See the climate section for record information for our climate sites, but all of these locations and many more are expected to be broken multiple days through Saturday...and not just a degree or two, as much as 5-6 degrees in cases like Barstow and Bishop. Consideration 2: Low temperatures. How cool the overnight period gets plays a significant role in ability for heat effects to compound over a period of time, both health related and infrastructure demands. Beginning as early as tomorrow morning, lows will struggle to fall below 80 degrees for the desert and river valleys and by mid week, struggle to fall below 90. This results in average temperatures through the 24 hour period above 100 degrees meaning AC units run basically all day and night, those without access to cooling experience no relief, and thus impacts increase. Again, this effect might be tolerated if happening over a day or so, but the forecast calls for several days of record breaking or near record minimum temperatures...potentially through the weekend. Consideration 3: Duration. Typically, heat waves that meet the above two considerations last for one or two days...three or more days, less than 6 times, and only once for 4 or more days (for KLAS specifically). Currently we are forecasting these conditions for *at least* 4 days, if not up to 6. Thus, the expectation is that impacts may initially be slow to build but increase significantly into the late week and weekend. Regarding impacts: The last time we experienced heat of this magnitude and duration was late June & early July 2013. During that event, southern Nevada saw nearly 30 fatalities and over 350 heat related injuries as well as temporary power outages. Some of those impacts were surely increased due to the 4th of July holiday period but nearly 2/3 of those fatalities occured while indoors...providing a clue that it isn't just increased outdoor recreation that led to those impacts. Thus, impacts to expect this week... - Rapid onset of dehydration, hyperthermia, heat cramps, heat stroke & heat exhaustion. - Extreme risk for children and pets if left in a hot vehicle even for minutes. - High demand for power consumption due to continued AC usage. Possible power outages and/or failing air conditioning units, providing inadequate daytime and nighttime cooling. There are more considerations that go into evaluating heat risk including vulnerability but given the magnitude of this expected heat wave, most if not all of the population will be at high or very high risk. The lengthy breakdown of the heat concerns in this discussion are specifically intended to contextualize this expected heat event vs others and to bust the myth that this is typical for the Desert Southwest. It isn't. && .FIRE WEATHER...A Red Flag Warning is in effect today from 11 AM until 9 PM PDT for NV Zones 460-464 and CA Zones 226/277 (Inyo County), due to gusty southwest winds and low humidity. Southwest winds will increase this morning reaching speeds of 20 to 25 mph with gusts between 30 and 40 mph. Minimum relative humidity levels will generally be less than 10 percent, with many lower elevations locations under 5 percent. Elsewhere across the area winds will see gusts generally less than 30 mph. Tuesday will bring one more afternoon of southwest winds 20 to 25 mph gusting between 30 and 40 mph primarily around central Nevada where a Red Flag Warning is in effect for Nevada Zones 460-462 from 11 AM until 9 PM PDT. && .CLIMATE...Listed below are a few climate locations showing both the record high maximum and high minimum temperature for each location and the year the record was last set for next Wednesday, Thursday and Friday. LOCATION WED-JUNE 16 THU-JUNE 17 FRI-JUNE 18 (HIGH MAX) Record(year) Record(year) Record(year) Las Vegas NV 114(1940) 113(1940) 115(1940) Bishop CA 104(1961) 104(2017) 107(1985) Barstow CA 110(2000) 110(2017) 112(1985) Needles CA 118(2000) 120(1917) 119(2017) Kingman AZ 110(1917) 108(1917) 109(2017) Desert Rock NV 103(2017) 106(2017) 108(2017) Death Valley CA 123(1917) 122(1917) 124(2017) Laughlin NV* 118(2000) 113(2017) 117(2015) Lake Havasu City AZ* 115(2000) 115(1985) 115(1985) * Not climate sites, but state temperature record holders. LOCATION WED-JUNE 16 THU-JUNE 17 FRI-JUNE 18 (HIGH MIN) Record(year) Record(year) Record(year) Las Vegas NV 87(2000) 87(2008) 86(2017) Bishop CA 68(1974) 65(2002) 69(2017) Barstow CA 80(1976) 78(1971) 79(1971) Needles CA 86(2000) 88(2000) 90(1988) Kingman AZ 76(1961) 79(1949) 73(2000) Desert Rock NV 79(2000) 75(2008) 82(2017) Death Valley CA 102(1917) 94(1961) 94(1961) && .AVIATION...For McCarran...Similar wind patterns are expected today compared to yesterday with breezy south to southwest winds developing this afternoon. Gusts to around 25KT are likely. Moderate confidence that a southwest or westerly push will move into the terminal around 00Z through the early part of the evening. Typical overnight wind patterns return tonight, with winds 8KT or less for the overnight period. Otherwise, FEW-SCT CIGs are expected at times around 25kft. High temperatures will climb to around 110 degrees this afternoon, with 100 degrees likely by 11AM. For the rest of southern Nevada, northwest Arizona and southeast California...Breezy southeast winds are expected again this afternoon at BIH, with gusts up to 30KT possible. A push of southwest to west winds is also possible this evening at BIH for a few hours around 00Z, with gusts 20-25KT if the west winds develops. If they dont, continued breezy southeast winds will persist until around 05Z. Elsewhere, south to southwest winds will gusts to 20-25 KT possible. By sunset, winds will decrease across the region with winds generally less than 10 knots overnight. DAG may continue to be breezy out of the west through the first part of the night. Mostly clear skies are expected with some passing high clouds. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && UPDATE...Czyzyk SHORT TERM/FIRE WEATHER...Adair LONG TERM...TB3/Peters CLIMATE...Peters AVIATION...Nickerson For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter
The national radar mosaic for the moment the first event began.
6 excessive heat. Local standard time, as filed.
Excessive Heat Warning criteria were reached seven days in a row.
Excessive Heat Warning criteria were reached seven days in a row.
Excessive Heat Warning criteria were reached seven days in a row.
Excessive Heat Warning criteria were reached seven days in a row.
Excessive Heat Warning criteria were reached seven days in a row.
Excessive Heat Warning criteria were reached seven days in a row.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2021Every state in 2021This day in weather historyWarnings in Nevada, June 2021
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: 969708, 969709, 969710, 969711, 969712, 969713.