Departing Aircraft Reach New Heights with Cold Temps

Two weeks ago, we shared the news article Airplanes and Cold Weather that describes why aircraft sound different when temperatures drop. It also noted that cold air has higher density which improves acceleration, reduces the runway length aircraft need during take-off, and increases lift and altitude gained as aircraft depart the airport.

And in fact, during the recent cold snap, aircraft did depart from Minneapolis-St. Paul International Airport (MSP) at much higher rates of climb than during warmer weather. The chart below shows departure altitudes during the last two weeks (February 5, 2021 through February 15, 2021) in blue and departure altitudes from last summer (June 29, 2020 through July 13, 2020) in red. To compare aircraft departure altitudes, concentric rings centered on the start of takeoff roll for each MSP runway were applied every mile between two miles and ten miles. Total average departure altitudes for flights at each ring are shown in the chart. 

Within three miles of MSP, aircraft were more than 300 feet higher during the cold snap. That would make aircraft more than a Minnesota Capitol dome above the same flight in hot temperatures. Further out, at nine and ten miles from MSP, aircraft altitudes averaged over 1,600 feet higher than during the summer. That distance would make aircraft more than two IDS Towers (excluding communications antennas) stacked on top of each other higher during the cold snap.