Technicians at the Oklahoma Mesonet perform three regularly scheduled site maintenance passes annually. During a pass, each of the 116 stations are visited. Over 1700 digital photos are taken during each pass to document the condition of each site and its surroundings. Each sensor is inspected and cleaned if necessary. The rain gauge is tested by dispensing a specified volume of water into the funnel and verifying that the correct number of tips is recorded. Wind speed sensors are checked for signs of worn bearings. Observations from the temperature, relative humidity, solar radiation, and pressure sensors are compared in the field to recently calibrated lab sensors. In addition, the tower hardware and power systems are inspected. Any sensor that is due for a scheduled rotation is replaced and returned to the Mesonet lab for calibration. Metadata gathered during each pass are organized on a website for easy access.