On 4 July, Montreal emergency services reported twelve hundred calls per day about the heat, up 30% from prior busiest days.
As of 10 July, seventy-four people, most of them already ill, had died heat-related deaths in Quebec. This province's death toll is reported as much higher than others' because of its looser rules for attributing death to heat. In Ontario, where only accidental deaths directly caused by heat are counted, the coroner's office is investigating three possible cases.
While the heat wave ended on 10 July in Central Canada, this was not so for the Maritimes. On the 23rd of July, the interaction between a far-northwest Azores-Bermuda High and a trough over Ontario led to the issuing of heat warnings for all three Maritime Provinces, with several locations reporting humidex values in excess of 36. In Halifax, the heat wave contributed to a record-breaking number of hot days in July, with the airport reporting daily high temperatures in excess of 25 degrees Celsius on twenty-two days that month, breaking the previous record of twenty-one days set in 2008, 2003, and 1924.
On 8 and 9 August, temperatures reached high levels in Metro Vancouver. The daily highs in Abbotsford were 35.6 °C (96.1 °F) and 34.1 °C (93.4 °F) respectively. Temperatures on the waterfront of Vancouver reached 31.0 °C (87.8 °F) and 30.8 °C (87.4 °F). The hottest temperature reached in the Lower Mainland was 36.5 °C (97.7 °F) in Cultus Lake.Cranbrook broke its record for August of 37.2 °C (99.0 °F), and the all-time record of 38.9 °C (102.0 °F), with temperatures reaching 40.5 °C (104.9 °F).Creston broke its August record of 38.0 °C (100.4 °F), reaching 38.7 °C (101.7 °F), but did not break the all-time record. The largest city to break an all-time record was Calgary, with temperatures reaching 36.5 °C (97.7 °F). The previous record for August was 35.6 °C (96.1 °F), while the all-time record was 36.1 °C (97.0 °F). Temperatures in Lethbridge reached 40.0 °C (104.0 °F), breaking the previous August record of 38.9 °C (102.0 °F), and tying its all-time record.
On 6 July, the temperature at UCLA was 111 °F (43.9 °C), breaking the all-time high temperature record of 109 °F (42.8 °C) set in 1939 but still 6 °F (3.3 °C) lower than the record 117 °F (47.2 °C) set in Woodland Hills, a Los Angeles neighborhood, at about 1 p.m. local time the same day, according to the weather service. Elsewhere in California, Santa Ana and Ramona hit respective record highs of 114 °F (45.6 °C) and 117 °F (47.2 °C). The combined conditions of heat and dryness fueled wildfires that caused one fatality and hundreds of evacuations. In Palm Springs the temperature reached 119 °F (48.3 °C).
On July 23 Palm Springs' temperature reached 119 °F (48.3 °C) again. On July 24 the temperature hit 121 °F (49.4 °C), two degrees Fahrenheit less than its all-time record set in July 1995.
California's state authorities and the California Independent System Operator both urged power conservation by people and business from 5 p.m. to 9 p.m. on July 24 and July 25, 2018. Flex Alerts were issued as the power grid began to overload. The Los Angeles County Department of Public Health also urged people to stay out of the sun on July 24. Thousands lost electricity in California due to sporadic temporary power cuts on July 24 as record temperatures hit the southwestern United States, including much of Arizona and parts of California and Utah.
The forest fires that started near the Sequoia and Yosemite National Parks on July 13 grew Jul 22, 2018. The fires were visible for several miles on the south side of the Mineral King Road and Slapjack Creek, a National Park officials said on July 22. The Atwell-Hockett Trail and the Tar Gap Trail are closed due to the fire, But the Sequoia and Kings Canyon National Parks remain open on July 22. A bulldozer on July 13 and 4 firefighters had died by July 22. More than 2,800 firefighters, a fleet of aircraft and bulldozers had contained only 7% of its perimeter by July 22. An air tanker dropped fire retardant drop on the Horse Creek Fire in Sequoia National Park.
By early June 2018, the Mexican government had declared a state of emergency in more than three hundred municipalities. The extraordinary sales of cold beverages, ice creams, pops and other items popular during hot weather increased to such an extent that Canacope Puebla, a Mexico City business chamber, estimated the nation's GDP would increase by approximately 260 million pesos ($13 mln).