A strong high pressure system developed across the region. As a result, a warming trend began early on August 5th with temperatures in the upper 90s to lower 100s.
Every event with a place to put it; 20 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 HNX wrote it up.
A strong high pressure system developed across the region. As a result, a warming trend began early on August 5th with temperatures in the upper 90s to lower 100s. Warming continued for the next several days as high pressure strengthened over our forecast area. Highs reached around 105 degrees for at least a few consecutive days, or until the 11th, in the Central Valley and over 110 degrees in the Kern County desert, with the hottest temperatures in the Indian Wells Valley. A slight lowering trend began on the 12th, but highs remained at least a few degrees above seasonal averages.
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 Aug 8, 8:30 PM PST, 3 hours 30 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Hanford CA 930 PM PDT Fri Aug 8 2025 .UPDATE...Aviation section updated. && .KEY MESSAGES... 1. A warming trend is underway as triple digit heat will be seen through early next week. 2. There is a 10 to 20 percent chance of high temperatures of at least 103 degrees Today before increasing to 40 to 60 percent chance during the weekend. 3. Minor fire risk with widespread minimum relative humidity between 15 and 25 percent for the non-desert areas. Minimum relative humidity expected to be less than 10 percent in the Mojave Desert with breezy winds in the afternoon to evening. && .DISCUSSION... High pressure now becoming the dominate feature over the West as shown in Thursday’s max temperatures. Ensemble upper-air analysis has the high showing signs of further amplification today and Saturday as Central California continues its warming trend. Probability of Exceedance (PoE) of reaching 100 degrees across the San Joaquin Valley now sits in the range of 70% to 90% plus between now and Monday afternoon. At the same time, PoE of reaching 105 degrees is still struggling to reach the 50% mark during the next four days with the best chances near Lemoore and the Interstate-5 corridor from Huron southward. Will see little change in the pattern until Tuesday. At which time, a disturbance moving through the Pacific Northwest will introduce a cooling trend as the region returns to near and below normal conditions later next week. Ensemble PoE has been very consistent with the onset of widespread triple digits across the San Joaquin Valley. Now that triple digits are upon us, the heat is on until early next week. Confidence remains high in keeping afternoon max temperatures in the 99 to 105 range during the period as probabilities diminish going outside of that range. By next Wednesday, best probabilities fall in the range between 95 and 100 degrees. Therefore, confidence in a cooling trend next Wednesday to Friday is growing. With the high pressure ridge shifting more off-shore during the weekend and into early next week. The flow aloft remains unfavorable for any Monsoonal moisture surges into Central California through early next week. With flow aloft showing a good westerly component, instability and a lack of moisture will keep any convection at bay as the area remains dry. Longer range ensembles show the same dry pattern through at least next Friday. && .AVIATION... 06Z Update: VFR conditions are expected in the San Joaquin Valley for 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 and/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... None. && public...Molina/BSO aviation....JPK/BSO weather.gov/hanford
The national radar mosaic for the moment the first event began.
20 excessive heat. Local standard time, as filed.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
Daytime highs generally ranged between 105 and 110 degrees each day between August 9 and August 11.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2025Every state in 2025This day in weather historyWarnings in California, August 2025
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: 1289893, 1289894, 1289895, 1289896, 1289897, 1289898, 1289899, 1289900, 1289901, 1289902, 1289903, 1289904, 1289905, 1289929, 1289932, 1289933, 1289934, 1289935, 1289936, 1289937.