Heat in California, May 7 to 31, 2001

Name: Heat in California, May 7 to 31, 2001
Start: 2001-05-07T14:00
End: 2001-05-31T18:00
Location: California

May 7 to 31, 2001 · NWS HNX · 2 events in 2 counties and zones

Unusual Weather: 9 days of 100+F. temperatures in May at Fresno shattered the old record of 5 days set in 1889 but Bakersfield had only 5 days.

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 2

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.

What happened

The episode as NWS HNX wrote it up.

Unusual Weather: 9 days of 100+F. temperatures in May at Fresno shattered the old record of 5 days set in 1889 but Bakersfield had only 5 days. The warmest May on record occurred in Fresno with Bakersfield the 2nd warmest. Temperatures jumped up near 20F above normal by reaching 100+F on the 8th in the San Joaquin Valley with subsequently several days of much above normal temperatures for much of the remainder of the month. Bakersfield ended the month with a max temperature of 107F on the 31st. Several max and min temperature records were reset at both Fresno and Bakersfield in the month. Considering the electrical power shortage and anticipated water shortfalls by the end of the warm season in Interior Central California, this early season jump to triple-digit high temperatures was unfortunate.

What forecasters said that day

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 May 7, 1:45 PM PST, 15 minutes earlier.

Area forecast discussion, May 7, 1:45 PM PST, 15 minutes before

INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION...RETRANSMITTED
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
245 PM PDT MON MAY 7 2001

UPPER RIDGE WAS CONTG TO SHIFT EAST THIS AFTERNOON WITH A WARM AND
DRY AIRMASS PARKED OVER THE CWA. PRESSURE GRADS WERE VERY SLOWLY
RESPONDING TO INTERIOR HEATING AS THERMAL TROUGH REMAINS ORIENTED
OVERHEAD...HOWEVER ANY WINDS THIS EVE SHOULD REMAIN CONFINED TO KERN
PASSES WITH A VERY WEAK NW FLOW DOWN THE CENTRAL/SOUTHERN SJ VALLEY.

ONCE AGAIN NO MAJOR INITIALIZATION PROBLEMS WERE EVIDENT WITH 12Z
MODELS. PROGS CONT TO SHOW RIDGE MOVING OVER THE INTERMOUNTAIN WEST
TONIGHT/TUES AS WEAK SHORTWAVE NEAR 43N/140W APPROACHES THE PAC NW.
ALTHOUGH THERMAL TROF WILL SHIFT EAST OF THE SIERRA...ONLY MINOR
CHANGES ARE INDICATED IN UPPER HEIGHTS WITH SLIGHT INCREASES IN BL
THICKNESSES. TEMPS SHOULD THEREFORE REMAIN WELL ABOVE SEASONAL
NORMALS WITH SOME LOCATIONS APPROACHING RECORD HIGHS. WITH AIRMASS
REMAINING VERY DRY...HOWEVER...LOWER ELEVATIONS SHOULD NOT APPROACH
CRITICAL HEAT INDEX LEVELS.

IN ADDITION TO WARM TEMPS...WILL NEED TO MONITOR MAGNITUDE OF
INCREASING ONSHORE GRADIENTS AHEAD OF WAVE ON TUES AND RATE AT WHICH
THE MARINE LAYER RESPONDS FOR POSSIBLE MARINE PUSH TUES EVE.
INSTABILITY AND AFTERNOON/EVENING CAPE WILL ALSO LINGER OVER HIGHER
SIERRA ELEVS...HOWEVER MOISTURE WILL REMAIN LIMITED AND EASTWARD
SHIFT IN THERMAL TROF SHOULD KEEP BEST POTENTIAL FOR ANY CONVECTION
EAST OF THE CWA.

MEDIUM RANGE PROGS ARE COMING INTO SLIGHTLY BETTER AGREEMENT
SHOWING A BROAD TROUGH SLOWLY EVOLVING OVER THE ERN PAC WED-MON.
DECREASING HEIGHTS AND THICKNESSES WILL RESULT IN GRADUALLY LOWERING
TEMPS OVER THE FA. WILL KEEP EXTENDED DRY AT THIS TIME...HOWEVER
WILL NEED TO MONITOR CONVECTIVE POTENTIAL OVER THE SIERRA THIS
WEEKEND AS PROGS ARE HINTING AT A POSSIBLE INCREASE IN MOISTURE BY
SAT.

.HNX...NONE.

JSN

Event by event

2 heat. Local standard time, as filed.

Heat, E Central Sj Valley

When: May 7, 2:00 PM PST to May 31, 6:00 PM PST
Where: E Central Sj Valley forecast zone
Reported by: OFFICIAL NWS OBS.

Heat, Se Sj Valley

When: May 7, 2:00 PM PST to May 31, 6:00 PM PST
Where: Se Sj Valley forecast zone
Reported by: OFFICIAL NWS OBS.

What these are

Heat: Heat below excessive heat criteria that still caused deaths, injuries or significant impacts.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 2001 Every state in 2001 This day in weather history Warnings in California, May 2001

Sources

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: 5244152, 5244153.