|North American heat wave of 2006|
|Dates||15 July, 2006 to August 27, 2006|
|Areas affected||Lower 48 U.S. states and lower parts of Canada|
|Reported Casualties||At least 225 dead|
The 2006 North American heat wave spread throughout most of the United States and Canada beginning on July 15, 2006, killing at least 225 people. That day the temperature reached 117 °F (47 °C) in Pierre, South Dakota, with many places in South Dakota that hit well into the 120s. A 130 degree temperature was reported is an remote farm in South Dakota. The heat wave went through several distinct periods:
In early reports from this heat wave, at least three died in Philadelphia, Arkansas, and Indiana. In Maryland, the state health officials report that three people have died of heat-related causes. Another heat related death is suspected in Chicago.
Although many heat related deaths go unreported, by July 19, the Associated Press reported that the soaring heat has already been blamed for 12 deaths from Oklahoma City to the Philadelphia area. Reports by early morning July 20 raised the death toll to at least 16 in seven states.
This period of heat also saw a wind storm (derecho) in St. Louis that caused wide-spread power outages, including for cooling centers designed to provide relief for those suffering from the heat. In addition, places on the West Coast, like California's Central Valley and Southern California experienced humid heat, which is unusual for the area.
At least 31 deaths due to the heat were reported in New York City by August 16. At least 13 died in Queens, 9 in Brooklyn, 5 in Manhattan and 1 in The Bronx. By the end of August, authorities totaled 40 deaths in New York, however a later mortality review in November 2006 revealed that heat was a factor in 140 deaths.
In the early August heat, Chicago saw at least 23 deaths, but the City was widely praised for avoiding the disaster that occurred in the 1995 Chicago heat wave which saw over 700 deaths. The City took steps to ensure vulnerable residents were protected, and individuals took responsibility for their neighbors.
By July 25, California authorities were documenting at least 38 deaths related to the heat in 11 counties. Temperatures reached 110–115 °F (43–46 °C) in the central valley of California July 23–24. State officials said it was the worst heat wave to hit Northern and Southern California simultaneously in 57 years. Front page newspaper coverage described some individual deaths. By July 29, the death toll mounted to at least 139, with the coroner's office in Fresno — overwhelmed — double-stacking bodies.
There were also reports of animal deaths in California, with a veterinarian reporting 15 heat-related pet deaths as early as July 24. The impact on farm animals and agriculture was also becoming apparent, with the death of more than 25,000 cattle and 700,000 fowl, prompting emergency measures by the state.
The California heat wave broke local records. According to some reports it was "hotter for longer than ever before, and the weather patterns that caused the scorching temperatures were positively freakish." Fresno, in the central California valley, had six consecutive days of 110 degree-plus Fahrenheit temperatures.
Beginning July 31 and into early August, the Midwest, Ontario, and Atlantic states also began experiencing the heat. Temperatures approached the 100 mark in Rochester, New York on August 1 and were coupled with the highest humidity the area has experienced in over 51 years. The heat index reached 110 °F that day. La Guardia Airport in New York City recorded three consecutive days above 100 °F. The temperature peaked at 102 °F on August 2, 2006. Colonial Downs, a horse track in New Kent County, Virginia, canceled horse racing because of the 100 °F heat. The Saratoga Race Course canceled racing at the horse track for the first time in its history on August 2, 2006.
By August 8, the heat wave had passed for most areas, but persisted in the South and Southeast, with continued reports of mortality in Oklahoma.
By mid-month, temperatures had soared to 42.1°C (107.8°F) at Lytton, British Columbia, with three straight days topping 41 °C (105 °F). Although various daily records have been broken, the only overall monthly records in a major city was in Winnipeg, Manitoba where July was the driest and had the highest average maximum temperature of any July on record. In Val Marie, Saskatchewan the average daily maximum July temperature was 32.3 °C (90.2 °F), about 5 °C (9 °F) higher than average.
Just north of Toronto at Buttonville Airport, the temperature reached 37.8 °C (100.4 °F) on August 1, 2006. On the same day, the nighttime minimum temperature in Toronto was the highest ever recorded, only dropping to 27.2 °C (81 °F). In Ottawa, the temperature reached 36.3 °C (97.5 °F), but with the humidity factored in, it reached an all-time humidex record of an oppressive 48 °C (118 °F) Record power consumption was recorded in Ontario when 27,000 MW was used by consumers.
Powerful thunderstorms affected parts of Ontario and Quebec on July 17 and July 30 in Peterborough, in eastern Ontario(Ottawa area) in the early morning hours of August 1 and again in Quebec, centred around Montreal that same evening. More than 450,000 people lost power in Quebec in that storm. On August 2, more storms associated with a relieving cool front caused heavy damage over a wide swath of central and eastern Ontario, resulting in 175,000 residents losing power and thousands of felled trees blocking roads. Eight tornadoes were confirmed in that region ranging from F0-F2 in strength, the largest single day tornado outbreak in Ontario since 1985. The intensity of these storms was fueled by the heat bubble to the south. These series of storms have killed at least four people and injured many others, in addition to extensive property damage and destruction of forested areas.
After early August 2006, the heat only had a sporadic impact through the remainder of the month, mostly in the West. Temperatures returned to normal or even below average in other parts of the country.