Accuracy of Rain Gauges

The accuracy of a rain gauge is limited. The design of most rain gauges allows them to capture only rain which is falling relatively straight down. In storms, high winds will be driving the rain at sharp angles, sometimes almost in a horizontal pattern. This can prevent the rain gauge from capturing the rain accurately. Spotty summer storms also make accurate rainfall totals difficult. A spot shower can easily dump an inch of rain on the rain gauge while a half mile away or less there was no rain received. Snow and ice can also distort data by blocking the collection tube.