Weather Station Maintenance Guidelines

The quality of the weather data collected and delivered via NEWA is highly valued for crop production and IPM forecast applications. Maintain your weather station in good working condition according to the manufacturer’s recommendations for optimum data integrity. Below are tips for relative humidity and temperature sensors, precipitation (rain) gauges, leaf wetness sensors, wind speed anemometers, wind direction weather vanes, and solar radiation sensors. Calibrate weather stations about every two years, contact the station manufacturer for calibration.

Routinely inspect your weather station to make sure all sensors are clean, free of debris and in good working condition. Periodically clean the solar panels that power the battery with a soft, clean, damp cloth. Inspect mounting brackets, poles, posts, etc. to make certain they are stable, vertical and sound and the instrument is securely fastened. Jostling during strong winds can affect radio transmission of data.

Protect weather instruments, sensors and cables from pruning, spraying and harvesting activities that may damage the sensors, cut cables, or cause weather stations to lean.

Relative humidity (RH) and temperature sensors:
These sensors are delicate instruments that should be periodically checked, according to the manufacturer's recommendations, to make certain they are accurate. Compare the readings of the weather station sensors with a calibrated thermometer or with another nearby weather station. During dewy mornings or rainy weather, low RH readings indicate a sensor malfunction. Contact the station manufacturer to replace bad or broken sensors.

Precipitation (rain) gauges:
Leaves, moss, algae and debris will cause clogging of the tipping bucket screen. The tipping bucket should be cleaned routinely (at least twice a year). The surrounding environment will affect how often it should be cleaned. For example, where weather stations are placed in an open area near an orchard, vineyard or woods, make sure that tipping bucket rain gauges are not subject to filling with leaf litter from adjacent areas.

For RainWise AgroMET (MKIII SP) stations, to clean the rain gauge pull the cotter pin out, remove the screen and clear the drain hole. You can clean the collector and tipping bucket with warm soapy water if necessary. Make sure you rinse it well afterwards. When putting it back together, if the cotter pin legs hang down inside the bucket collector, they may interfere with the tipper mechanism. The cotter pin legs MUST be bent up so they don’t interfere with the tipper.

Wasps may build nests in tipping bucket rain gauges. A small piece of vapona strip may be used as a deterrent.

If improperly mounted, the weather station may be jostled during strong winds and this may cause the tipping bucket arm to tip and record a small amount of precipitation during dry weather.

If the rain gauge continues to malfunction after cleaning, it is possible the reed switch is bad. Contact the station manufacturer for technical support or replacement.

Leaf wetness sensors:
NEWA suggests that you place plastic grid type leaf wetness sensors facing north and angled 45 degrees from horizontal. If they are attached close to the weather station, this protects the sensor and cables from pruning, spraying and harvesting activities. Periodically check the plastic grid for cracks that would expose the metal wire grid. Contact the station manufacturer to replace any broken or cracked leaf wetness sensors.

Wind speed, anemometers:
The anemometer should spin freely and be free of debris of any kind. Periodically inspect the anemometer in strong wind conditions and calm conditions and check the data being recorded to make certain it is working correctly. Contact the station manufacturer for technical support or replacement.

Wind direction, weather vane:
The weather vane should be set to zero on due North in order for the readings to be accurate. Any time the weather station is moved or bumped, check the orientation of the weather vane relative to North. The weather vane should move freely and be free of debris of any kind.

Solar radiation:
The solar radiation sensor must be kept clean to ensure accurate readings. Clean the glass diffuser with a damp cloth. Replace the diffuser when it yellows (usually after several years of service). It is essential to have good solar radiation readings in order to run the apple carbohydrate thinning model. If your station does not appear in the selection list of stations for that model, the solar radiation data is out-of-range. Should this become an issue, contact the station manufacturer about sensor calibration or replacement.

Routinely inspect your weather station to make sure all sensors are in good working condition, it is in a vertical position, and firmly secured to its mounting post. Calibrate weather stations about every two years, contact the station manufacturer for calibration.

Carroll and Gibbons, 2014
jec3@cornell.edu