This paper is an analysis of the first formal monitoring of solar insolation in Reno, which began in 1979. The observed data were compared point by point with the ASHRAE equation for solar irradiation, modified for altitude. Predicted clear day flux was greater than observed, with the difference increasing above SZ at high zenith angles. Observed insolation was correlated with total sky cover. The decrease in insolation was less than that observed by other investigators.

Units: I-P