Southwest US preps for 120 temps: Water, water, more water

But three of the four hottest days on record in Phoenix, including the all-time high of 122 degrees on June 26, 1990, have occurred in June. The city could gamble with its highest temperature ever observed, which was 117 degrees Fahrenheit in 2013.

Sacramento, California, saw record high temperatures of 106 degrees on Sunday, heat last seen nearly 75 years ago, when it reached 105 degrees Fahrenheit.

American had not canceled any Monday flights to or from Sky Harbor as of noon, an American spokeswoman confirmed, adding that Tuesday's canceled flights include both departures and arrivals. The excessive heat warning will be in effect until Friday night.

City authorities issued an excessive heat warning and urged people to stay inside and stay hydrated. I hope everyone takes the risk of unsafe heat seriously and takes advantage of whatever relief options they have.

Predictions are for as many as 10 very hot days, with numerous high-temperature records likely to be broken as the heat sets in.

In addition to grounding flights of smaller planes, airlines have been taking other measures on larger jets to reduce their weight because of the heat.

American Airlines announced Monday that it has canceled its regional flights - approximately 45 flights - for Tuesday, June 20.

To stay cool, residents of San Francisco can head over to a cooling center in their neighborhood, especially if their home does not have air conditioning.

"Surface temperatures will reach into the 110s F and even 120s F in some places across the region", AccuWeather Meteorologist Jordan Root said.

The airline, which operates its second-busiest hub at Charlotte Douglas International Airport with around 650 daily flights, is offering American flyers the option to change their plans without a fee.

American Airlines said in a statement that the American Eagle regional flights use the Bombardier CRJ planes which can not operate at temperatures above 118 degrees.

Forecasters also warned Phoenix could hit 120 degrees this week.

Weather service meteorologist Ashley Allen says the Strip's tall, close buildings and long stretches of concrete cause the area to heat quickly and cool slowly.

He says second and third degree burns from hot asphalt and concrete, playground equipment, auto and truck interiors and scalding water from outdoor hoses are common when temperatures exceed 100 degrees.

  • Larry Hoffman