During cold weather, how does an altimeter typically perform?

In cold weather conditions, an altimeter, which measures altitude based on air pressure, can indeed give a higher than actual altitude reading. This occurs because the altimeter is calibrated to standard atmospheric conditions, which are based on a specific temperature profile. When temperatures are colder than this standard, the air becomes denser and the pressure at a given altitude is higher than the standard atmospheric pressure. As a result, the altimeter interprets this higher pressure as indicating the aircraft is at a lower altitude than it actually is, leading to an overestimation of altitude.

Understanding this behavior is crucial for pilots, especially in cold weather scenarios, as it emphasizes the importance of adjusting for temperature variations to ensure safe and accurate altitude readings during flight operations.