Does anyone have a procedure for calculating a long term average for wind direction? I have my WiFiLogger 2 set to transmit weather data every 3 minutes. I want to calculate averages of wind speed, direction, air temperature and humidity and max-windspeed every hour to display on a website graph. As a first approximation I save both direction and pseudo-direction i.e. deviation from 0 which can be positive or negative. Averaging the pseudo-direction works fairly well if the directions are from 270 - 180 and average direction works well if the directions range from 0 to 270. But bugs can arise and average of a wind mainly from the S can become a N wind. There must be a recognised procedure because lots of anemometer systems average direction albeit mostly for shorter times.