The measared of near‐surface and upper‐air temperature and humidity is required during flyover noise tests to adjust the noise data to reference‐weather conditions or to classify the data with respect to various criteria. Parallel advancements in equipment, test techniques, and noise data adjustments have occurred in the last several years at the Douglas Aircraft Company. Measurements of near‐surface temperature and humidity began with a psychrometer hand‐held at four feet above the ground and subsequently evolved through a series of instrument types mounted 33 feet above the ground on a trailered tower. Upper‐air (or sound‐path) weather data were initially acquired from local weather bureaus and later from various instrumented light aircraft. The more notable improvements are the use of dew‐point sensors for humidity measurements, increased data sample rates, and system performance monitoring. Current instruments, along with sufficient attention to time and space dependencies, appear to furnish an adequate definition of the test atmosphere. However, more data are required to quantify and evaluate the actual accuracy of the system.