Phoenix 122°F Record: How Extreme Heat Halted Sky Harbor Airport Flights

January 2, 2026 at 12:01 PM•3 min read

Sky Harbor International Airport operations halted on June 26, 1990, when the 122°F record heat exceeded aircraft performance charts, forcing airlines to develop new takeoff procedures.

Key Points

1122°F, the all-time Phoenix temperature record set on June 26, 1990, caused a grounding at Sky Harbor International Airport (PHX).
2The grounding occurred because existing aircraft performance charts did not include data for temperatures above 120°F, preventing safe takeoff calculations.
3The event led to a permanent industry change, forcing manufacturers like Boeing and Airbus to extend performance data to 127°F to manage density altitude effects.

On June 26, 1990, Sky Harbor International Airport (PHX) faced an unprecedented operational crisis. The air temperature in Phoenix reached a historic 122°F (50°C). This temperature remains the city's all-time record high. The extreme heat forced a temporary grounding of commercial flights. This was not due to mechanical failure. Instead, it exposed a critical gap in aircraft performance charts.

Density Altitude and Operational Limits

High temperatures severely impact aircraft performance. Heat causes the air to become less dense. This effect is measured as density altitude. Thinner air reduces engine thrust and wing lift. Consequently, planes require more runway for a safe takeoff.

In 1990, many airlines' performance charts stopped at 120°F. This meant pilots could not calculate the required runway length. They also could not determine safe takeoff weight. America West Airlines, then Sky Harbor's largest carrier, postponed takeoffs. They were unsure how the heat would affect their Boeing 737 fleet.

Southwest Airlines also halted flights briefly. They waited for instructions from Boeing. The delays lasted about two hours. The issue was not that the aircraft could not fly. The problem was that no one had anticipated needing data for such high temperatures.

Industry Response and Lasting Change

The 1990 grounding was a wake-up call for the aviation industry. It highlighted the need for greater high-temperature aviation safety planning. In the months following the event, airlines and manufacturers made adjustments. They updated their aircraft performance charts to exceed 120°F.

Today, most modern mainline fleets, including those from Airbus, have data for temperatures up to 127°F. This change allows for continued operation in extreme heat. However, the heat still necessitates operational adjustments. Airlines often manage the heat by reducing the aircraft's gross weight. This is typically done by limiting cargo.

Regional jets, however, can still face limits. Some smaller aircraft may have takeoff limits below 120°F. This can still lead to delays or cancellations. The Federal Aviation Administration (FAA) emphasizes density altitude training. They advise scheduling operations during cooler hours. This helps mitigate the impact of high density altitude flight restrictions.

Key Details

The Phoenix all-time temperature record of 122°F was set on June 26, 1990.
The grounding was due to aircraft performance charts not extending past 120°F.
The event spurred manufacturers to update data for extreme heat aircraft operations.
Today's procedures involve weight restrictions to manage density altitude.

The 1990 event remains a critical lesson in airport operational challenges. It underscores the relationship between meteorology and commercial aviation news. For more information on aviation safety, visit our commercial aviation news section.