Heat in California, July 16 to 27, 2006

Arguably one of the hottest spells widespread across California, including Interior Central California, in the last 75 years occurred during a warm period that spanned from the 16th through the 27th of the month. Fresno City had 12 days in a row where maximum temperatures were at or above 105 degrees F. Numerous daily maximum and high minimum temperature records were both reset including the all-time high minimum temperature record for Fresno at 90F on the 23rd from that of 86F set in August of 1908. During the 5-day period from the 22nd through the 26th, Fresno had temperatures of 110F+ each day. The Southwest San Joaquin Valley maximum temperatures had 110F+ readings for a 6-day period from the 21st through the 26th. Minimum temperatures during that warmest portion of the heat spell lowered only into the 80s for much of the Central and South San Joaquin Valley. Even the high foothill areas and Kern County Mountains were impacted as Yosemite Valley in the Southern Sierra Nevada at the 4000-foot elevation had maximum temperatures of 100F+ from the 22nd through the 27th with a 105F high on the 26th. In the high desert areas of Kern County Inyokern had 110F+ from the 22nd through the 27th with overnight lows in the upper 70s to around 80F. Several daily high temperature records were also established in the Kern Desert during the period. Peak energy use in the state hit an all time record, 6165 Megawatts, even though several thousand customers in Central California went without power and air conditioning for hours. Typical of the situation $100K of refrigerated products were lost at a single store in Northwest Fresno during a power outage on the 24th. Among the documented instances of power loss during the heat event, Fresno had 11,000 power customers without electricity on the 22nd and 14,000 on the 23rd. All 10,000 power customers in Lemoore in Kings County lost electricity for up to 4 hours during the afternoon of the 23rd, one of the hottest days, as power transformers failed in the heat. In Tulare County, portions of Exeter lost power during the evening of the 24th. With accompanying high humidities, consistent light or calm winds, and long durations of high temperatures, the heat resulted in many deaths among residents of Interior Central California as well as a tremendous toll on area agriculture and specifically the dairy and cattle industry. Up to 57 people died as a result of the excessive heat in the Interior Central California 7-county area. Many but not all of these deaths were among the elderly and in urban areas. Milk and egg production losses were estimated at 10 to 15% during the heat spell along with an increase in livestock deaths (16,500 cows) and poultry deaths (700,000 chickens and 160,000 turkeys). Diminished yield in produce from field crops and orchards undoubtedly occurred and losses could only be estimated due to difficulties in assessing. One local county, Kings, estimated losses at 20% for almond production with $10 million in other crop losses. In addition to the loss of livestock and poultry due to the heat, area counties declared local emergencies due to rendering problems caused by the high number of livestock and poultry carcasses.