2018 North American heat wave

The 2018 North American heat wave was a heat wave in some parts of North America. At least 70 deaths in Quebec were heat-related.[1] Eighteen states between Michigan and New Mexico issued heat advisories to over 60 million people.[2]

Eastern Canada[]

From July 1 to July 6, 2018, the air temperature consistently rose above 35 °C (95.0 °F) in parts of Quebec and Ontario. The humidex value for Ottawa on Canada Day between noon and 3 pm was 47, the highest ever recorded in the city.[3] The heat wave also affected the Maritimes, with the humidex value hitting a record-breaking 45 in Greenwood, Nova Scotia.[citation needed]. On July 4, Montreal emergency services reported 1200 calls per day about the heat, up 30% from prior busiest days.[4]

As of July 10, 74 people, most of them already ill, had died heat-related deaths in Quebec.[5][6] The province's death toll is much higher than others because of its looser rules for attributing death to heat.[7] In Ontario, where only accidental deaths directly caused by heat are counted, the coroner's office is investigating three possible cases.[5]


On July 6, temperatures in southern California went over 110 Fahrenheit (43° C).[citation needed] Santa Ana and Ramona hit respective record highs of 114 degrees F (46° C) and 117 degrees F (47° C).[citation needed]

The heat and dryness exacerbated conditions fueling wildfires, which have caused one fatality and hundreds of evacuations.[8][9]

On July 7, 34,500 Los Angeles Department of Water and Power customers (2.5% of its base) experienced power outage, some for up to 24 hours. The day prior, peak energy demand set a new record for any July day in the city, at 6,256 megawatts.[10][9]


The temperature in Denver, Colorado on June 28 tied the city's record at 105 degrees Fahrenheit (41° C).[11] The record was set in 1878, then matched in 2005 and 2012.[12]