Reliability of hourly precipitation data

Properly exposed, calibrated, and evaluated, the customary 8-inch-diameter weighing rain gage yields hourly precipitation values with standard errors of about .01 inch, so that reliability within .02 inch can be assumed. But two identical gages 10 feet apart on a windy ridge top can differ consistently in catch by 50 per cent of the smaller. Four pairs of identical gages, exposed side by side at four sites in Santa Barbara County, California, January–April 1959, were studied.