A meter for determining chill temperature and/or comfort index. This meter utilizes a composite sensor that is responsive to the environmental factors that produce a chill temperature as perceived by a person in that environment. Specifically, the sensor is responsive to the combined effects of wind velocity, real temperature, solar radiation and humidity. In the most general embodiment, the output signal from the sensor is fed to a programmed microprocessor wherein that signal is repetitively sampled, averaged and converted to an appropriate signal so as to be appropriately displayed. In order to prevent adverse affects upon the average by spurious large signals, the microprocessor is programmed to limit any sample signal to a value that differs from the average by only a selected amount. The normal signal from the sensor is proportional to the square root of the power, and the microprocessor first squares that signal prior to the averaging step. Since the sensor produces an analog signal, and the microprocessor uses digital signals, an analog-to-digital converter is used. In those instances where it is desired to accentuate the effect of a specific environmental factor, a complimentary sensor for that factor is used to produce a modification of the average value and thus cause the generation of a selected response for the meter.