A number of Phoenix flights were cancelled in Arizona due to extreme weather conditions.

Arizona has been experiencing extreme heat lately, even when compared to usual weather conditions in the state in late June. More than 40 flights have been cancelled in Phoenix due to temperatures potentially reaching 120 degrees Fahrenheit.

The city’s all-time high is 122 degrees Fahrenheit, which happened back in June 1990. The Boeing aircrafts that were slated to fly out of Arizona are not supposed to be in flight if the temperature is above 118 degrees, which amounts to roughly 48 degrees Celsius.

The flights that were cancelled were expected to leave Phoenix between 15:00 and 18:00 local time. It is unclear whether or not airlines will refund passengers or re-schedule their flights in a timely fashion. but many will have to find alternatives if they wish to make their vacations or business trips.

The International Civil Aviation Organization (ICAO) warned that “have severe consequences for aircraft take-off performance, where high altitudes or short runways limit the payload or even the fuel-carrying capacity.”

Temperatures are expected to fall below the 100-degree mark after 8 p.m., so perhaps passengers will be able to travel beyond that.

Part of why the country has been experiencing extremely high temperatures lately revolves around the fact that climate change is affecting the planet more than ever over recent years.