That month also saw similar flight cancelations due to heat. But the hottest temperatures aren't even expected to arrive until Tuesday.
But it looks as though Flagstaff won't set a record high temperature for the date - the reading of 92 degrees just before the deluge was one degree off the record of 93 degrees for June 19 set just previous year.
Las Vegas was forecast to hit 117F (47.2C) on Tuesday and excessive heat warnings cover nearly all of California.
Gulf of Mexico should expect a totally different weather trend this week.
The forecast called for a high of 120 degrees (49 degrees Celsius) in Phoenix, 119 in Palm Springs, California, and 126 in Death Valley.
As temperatures are set to soar to record-breaking levels across the southwestern part of the United States this week, the health dangers can not be underestimated.
Larger jets, like Boeings and Airbuses, are able to withstand temperatures of about 127 degrees, allowing them to operate in extreme temperatures like those in Phoenix Tuesday. That maximum is set by Bombardier, the manufacturer. They can lighten the plane's load by selling fewer seats - a tactic American Airlines is using in the Phoenix heat wave - or reducing cargo.
Las Vegas also was expected to tie its all-time hottest mark of 117 degrees.
PHOENIX (AP) The southwestern U.S.is about to feel the wrath of a punishing heat wave that includes a forecast of 120 degrees in Phoenix a temperature not seen in the desert city in more than 20 years. U.S. today reports that temperatures reached 122 back in 1990. "It looks like (Tuesday) is the peak of the heat wave", Hernandez says. The latest batch of heat will cook an area from northern California to western Texas, a region home to some seven of the 10 fastest-warming cities in the country.
The heat is on along the west coast with record highs expected.
Visitors should be aware of a little-known fact about the temperatures in the gambling mecca: The Strip is often hotter than the rest of the city.
As temperatures increase, more people use air conditioners, which uses a lot of electricity and can strain the power system. Steering wheels and vehicle shifters can be too hot to touch when getting into a auto.
People showed up at a PetSmart store in Tempe on Tuesday to receive free booties to put on their pets' paws so they don't burn on concrete and pavement. The reason: extreme heat.
The main burn center in Phoenix warned people to be careful around vehicle interiors and pavement and with their pets.
Foster says young children are particularly vulnerable because their skin is more sensitive.
Phoenix is experiencing one of the worst heatwaves in decades.