A large upper ridge which was centered over the four corners area built westward and strengthened over central California between June 15 and June 18 resulting in dangerously hot daytime temperatures becoming prevalent over the Kern County Deserts by June 15 and over the Lake Isabella and Tehachapi areas by June 17. The heat surged into the San Joaquin Valley, West Side Hills and Sierra…
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 HNX wrote it up.
A large upper ridge which was centered over the four corners area built westward and strengthened over central California between June 15 and June 18 resulting in dangerously hot daytime temperatures becoming prevalent over the Kern County Deserts by June 15 and over the Lake Isabella and Tehachapi areas by June 17. The heat surged into the San Joaquin Valley, West Side Hills and Sierra foothills by June 19 as daytime highs were 110 Degrees F or higher at several locations. Temperatures cooled slightly on June 20 and more significantly on June 21 and 22 as the ridge shifted to the east of the area.
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 Hanford, CA wrote its last area forecast discussion before the first event at Jun 15, 3:44 AM PST, 6 hours 16 minutes earlier.
Area Forecast Discussion National Weather Service Hanford CA 444 AM PDT Tue Jun 15 2021 .SYNOPSIS... A ridge of high pressure will build westward from the 4 corners region this week bringing dangerously hot, life-threatening temperatures. The heat will start in the Kern county desert today and will then spread into the rest of the central California interior Wednesday through the end of the week. && .DISCUSSION... Satellite loops showing clear skies across the central California interior this morning as we remain under a dry southwest flow aloft. This flow is being directed between a trough of low pressure off the Pacific Northwest coast and a ridge of high pressure over the Four Corners Region. The trough will swing inland today as the high pressure ridge strengthens and begins to build westward over southern California. As a result, temperatures will climb several degrees higher in the Kern County Desert today while the rest of the district sees only a slight increase. An Excessive Heat Warning begins for the Kern County Desert today with high temperatures near 110 degrees in parts of the Indian Wells Valley. The trough lifts northeast into Canada on Wednesday allowing the dome of high pressure to expand across California. Lower elevations in the Kern County Mountains around Lake Isabella and Tehachapi go under the Excessive Heat Warning on Wednesday as the dangerous heat expands. Widespread triple digit heat will begin to affect the rest of the lower elevations on Wednesday too but not to critical levels yet. That happens on Thursday with much of the San Joaquin Valley forecast to be around 108 degrees. Friday is currently expected to be the hottest day with SJ Valley highs around 110 degrees. Saturday will be only a degree or two lower. An Excessive Heat Warning goes into effect for the SJ Valley, the West Side Hills, and the Sierra Foothills on Thursday and goes through Saturday. Some record high temperatures may be approached on Thursday with record breaking heat more likely on Friday and Saturday. The NBM (National Blend of Models) gives Fresno a 50% chance of reaching 110 degrees or higher on Friday and a 19% chance of reaching 112 degrees or higher. The NBM gives Bakersfield a 39% chance of reaching 110 degrees or higher on Friday and an 11% chance of reaching 112 degrees or higher. Model ensembles agree with the ridge weakening a bit over the weekend and more early next week. So while we are entering a heat wave that will last several days, the forecast has temperatures lowering to the mid 90s in the SJ Valley by Tuesday of next week, which is only slightly above normal. && .AVIATION... VFR conditions can be expected throughout the central California interior for at least the next 24 hours. && .AIR QUALITY ISSUES... None. && .CERTAINTY... The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information an/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Excessive Heat Warning from 10 AM this morning to 8 PM PDT Saturday for CAZ198-199. Excessive Heat Warning from 10 AM Wednesday to 8 PM PDT Saturday for CAZ195-196. Excessive Heat Warning from 10 AM Thursday to 8 PM PDT Saturday for CAZ179>191-197. && Public/Aviation/Fire Wx........DCH PIO/DSS........................JEB weather.gov/hanford
17 excessive heat. Local standard time, as filed.
Daytime highs ranged between 106 and 112 degrees on June 15, 18 and 20 and between 110 and 116 degrees on June 16, 17 and 19.
Daytime highs ranged between 106 and 112 degrees on June 15, 18 and 20 and between 110 and 116 degrees on June 16, 17 and 19.
Daytime highs ranged between 102 and 107 degrees on June 17, 18 and 19.
Daytime highs ranged between 102 and 107 degrees on June 17, 18 and 19.
Daytime highs ranged between 101 and 106 degrees on June 17, 18 and 20 and between 104 and 109 degrees on June 19.
Daytime highs ranged between 101 and 106 degrees on June 17, 18 and 20 and between 104 and 109 degrees on June 19.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
Daytime highs ranged between 108 and 113 degrees on June 18 and 19 and between 106 and 111 degrees on June 20.
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, 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: 955575, 955576, 955578, 955579, 955591, 955592, 955580, 955581, 955582, 955583, 955584, 955585, 955586, 955587, 955588, 955589, 955590.