High pressure ridging brought hot temperatures across the area, 8 to 15 degrees above normal. Some locations had high temperatures reaching 109-113, with temperatures remaining in the mid to upper 70s overnight, locally in the low 80s in the foothills.
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 ridging brought hot temperatures across the area, 8 to 15 degrees above normal. Some locations had high temperatures reaching 109-113, with temperatures remaining in the mid to upper 70s overnight, locally in the low 80s in the foothills. Heat Warnings and Advisories were issued. Heat Risk Criteria reached Moderate levels across the forecast area, with some areas in the northern Sacramento Valley and adjacent foothills reaching High to Very High levels.
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 Jul 23, 1:26 PM PST, 17 hours 34 minutes earlier.
Area Forecast Discussion National Weather Service Sacramento CA 226 PM PDT Mon Jul 23 2018 .SYNOPSIS... Hotter weather returns this week, peaking Wed/Thu. Potential for an isolated afternoon shower or thunderstorm in the mountains continues into Tuesday. && .DISCUSSION... Strong upper ridging extending from the Desert Southwest will result in hotter temperatures across portions of Interior NorCal this week. AMS warms under increased subsidence with triple digit heat expanding over the Central Valley through midweek. Wednesday into Thursday look to be the hottest days this week. Although marine layer depth is expected to remain somewhat shallow, a moderate to strong Delta breeze will help to taper some of the heat in the Delta region, and to a lesser extent in the Southern Sacramento and Northern San Joaquin valleys. Afternoon visible satellite imagery showing TCU over our portions of the Coastal Range and from the mountains of Eastern Shasta south to the higher terrain of the Northern Sierra Nevada. Isolated afternoon to early evening showers or thunderstorms will be possible in these areas, but bulk of activity looks to be near the Sierra Nevada crest eastward. On Tuesday, midlevel flow begins to take on a SWly component, with slight chance of afternoon thunderstorms confined to near the Sierra Nevada crest. SWly becomes more dominant Wednesday, and thus expect any afternoon storms will be east of the Sierra Nevada crest. PCH && .EXTENDED DISCUSSION (Friday THROUGH Monday) High pressure will continue to bring hot temperatures across most of the region through the extended period. Both GFS and ECMWF guidance hint at an amplification of the pattern toward the weekend into next week with the ridge building into the Great Basin. This could result in stronger onshore flow through the Bay Area, and modest cooling in Delta Breeze influenced locations. Dang && .AVIATION... VFR conditions the next 24 hours. Isolated thunderstorms possible higher terrain through 03Z. Southwest winds 15-25 kts with gusts up to 30 kts near the Delta, elsewhere generally less than 10 kts. IDV / Dang && .STO WATCHES/WARNINGS/ADVISORIES... Heat Advisory from noon Tuesday to 11 PM PDT Thursday for Central Sacramento Valley-Clear Lake/Southern Lake County- Motherlode-Mountains Southwestern Shasta County to Northern Lake County-Northeast Foothills/Sacramento Valley-Northern Sacramento Valley-Northern San Joaquin Valley-Shasta Lake Area / Northern Shasta County. &&
5 heat, 3 excessive heat. Local standard time, as filed.
The NWS Experimental Heat Risk reached High to Very High readings that prompted an Excessive Heat Warning for the northern Sacramento Valley. Redding highs were 108 on the 24th, then reached 111 on the 25th and 113 on the 26th. Lows were in the 70s, peaking at 78 on the 24th.
The NWS Experimental Heat Risk reached High to Very High readings that prompted an Excessive Heat Warning for the Central Sacramento Valley. Marysville highs were 104 on the 24th, then reached 108 on the 25th and 102 on the 26th. Lows were in the mid to upper 60s.
The NWS Experimental Heat Risk reached High to Very High readings that prompted an Excessive Heat Warning for the mountains of southwest Shasta County to northern Lake County. Arbuckle Basin highs were 98 on the 24th, then reached 103 on the 25th and 106 on the 26th. Lows were in the upper 70s, peaking at 80 on the 26th.
The NWS Experimental Heat Risk reached Moderate to High readings for several days prompting a Heat Advisory for northern Shasta County.
The NWS Experimental Heat Risk reached Moderate to High readings for several days prompting a Heat Advisory for northern San Joaquin Valley. Modesto reached 102 on the 24th, 106 on the 25th, 104 on the 26th. Lows were in the mid to upper 60s.
The NWS Experimental Heat Risk reached Moderate to High readings for several days prompting a Heat Advisory for the southern Sacramento Valley. Downtown Sacramento peaked at 109 on the 25th. Lows were in the mid 60s.
The NWS Experimental Heat Risk reached Moderate to High readings for several days prompting a Heat Advisory for northern San Joaquin Valley. Knoxville Creek reached 101 on the 24th, 104 on the 25th, 106 on the 26th. Lows were in the mid to upper 70s.
The NWS Experimental Heat Risk reached Moderate to High readings for several days prompting a Heat Advisory for northeast foothills of the northern Sacramento Valley. Highs were in the low 100s, lows were in the mid to upper 70s to lower 80s.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2018Every state in 2018This day in weather historyWarnings in California, July 2018
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 2026-10-01. Each event’s entry at NCEI: 775973, 775974, 775975, 775977, 775978, 775980, 775984, 775985.