High pressure over California resulted in very hot daytime temperatures and warm overnight low temperatures across interior Northern California. High to very high heat risk impacted the region.
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 STO wrote it up.
High pressure over California resulted in very hot daytime temperatures and warm overnight low temperatures across interior Northern California. High to very high heat risk impacted the region. Two daily high temperature records were broken. During the event, cooling centers were made available to the public across interior Northern California.
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 Sacramento, CA wrote its last area forecast discussion before the first event at Aug 14, 3:05 AM PST, 8 hours 55 minutes earlier.
Area Forecast Discussion National Weather Service Sacramento CA 405 AM PDT Sat Aug 14 2021 .SYNOPSIS... High to locally very high heat risk is expected for much of the region this weekend. Mostly dry weather forecast except for a few mountain thunderstorms through the weekend. Not as hot early next week. && .DISCUSSION... Partly to mostly cloudy skies cover the region early this morning from a combination of wildfire smoke and some mid and high clouds from the remnants of former TS Kevin, though most of its remains are moving north off the coast. Onshore flow has weakened considerably since early Friday, and current temperatures are very mild compared to 24 hours ago ranging from the upper 60s to lower 80s through the Central Valley. High pressure will strengthen over the area this weekend resulting in widespread high, with locally very high, heat risk, especially for the Central Valley and adjacent foothills. Wildfire smoke may help to keep temperatures down locally, but lower elevation areas that see sufficient insolation will see highs above 105 with potential for 110 or above across the northern Sacramento Valley. Overnight lows will remain very mild the next several nights as any Delta influence will be minimal. Heat Advisory remains in effect. Late day storms will likely be a little more isolated today as developing updrafts will have to overcome the building ridge. Any storms that do develop will have the potential for gusty outflow winds and some lightning with little rain. A few late day storms will be possible again on Sunday. Temperatures will cool off a bit on Monday as a trough approaches, and then stronger cooling is expected Tuesday as temperatures return to close to normal. Locally breezy winds will be possible this trough passes Monday into Tuesday. The strongest winds will be seen in favored terrain, over ridges, and in the Delta region. && .EXTENDED DISCUSSION (Wednesday THROUGH Saturday)... Most ensemble clusters advertise a weak trough lingering over NorCal later next week as strong ridging develops upstream over the eastern Pacific. Airmass is likely to remain too dry/stable for diurnal deep convection over the mountains. Temperatures expected to be a little above average, though wildfire smoke will undoubtedly continue to impact them from day-to-day. && .AVIATION... VFR conditions expected the next 24 hours, except for areas of MVFR/IFR conditions vicinity wildfires. MVFR likely to predominate at KRDD. Elevated smoke layers from 040-060. Local southwest wind gusts 20-30 kts vicinity west Delta, otherwise gusts generally less than 12 kts. && .STO WATCHES/WARNINGS/ADVISORIES... Heat Advisory from noon today to 7 PM PDT Sunday for Central Sacramento Valley-Motherlode-Mountains Southwestern Shasta County to Western Colusa County-Northeast Foothills/Sacramento Valley-Northern Sacramento Valley-Northern San Joaquin Valley- Shasta Lake Area / Northern Shasta County-Southern Sacramento Valley. &&
7 excessive heat. Local standard time, as filed.
Lake Shasta Dam area saw high temperatures reach 110 to 114 degrees during the event.
The Northern Sacramento Valley saw high temperatures reach in excess of 111 degrees. Two daily high temperature records were set on the 15th with Redding airport reaching 116 degrees and Red Bluff Airport reaching 112 degrees during the event.
The Central Sacramento Valley region saw high temperatures reach in excess of 109 degrees during the event. On August 14th, Marysville recorded a high temperature of 103 degrees.
The Sacramento region saw high temperatures reach 105 degrees. On the 14th, downtown Sacramento recorded a high temperature of 103 degrees.
The Northern San Joaquin Valley saw high temperatures reach over 100 degrees during the event.
The Motherlode region saw high temperatures reach upwards of 100 degrees during the event. A temperature of 104 degrees was reported near Placerville, CA.
The western foothills of the Sacramento Valley saw high temperatures reach upwards of 113 degrees during the event.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2021Every state in 2021This day in weather historyWarnings in California, August 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: 987002, 987003, 987009, 987010, 987012, 987013, 987014.