A guide to selecting and installing a weather station on your property.

Weather Stations may be placed for general use or for specific purposes on a property such as for frost protection or controlling irrigation hardware. The intended purpose of a weather station will inform its location. For frost protection this means locating it in the cold spots of a property. It is important to install weather stations in the best location for its purpose and to ensure they are maintained properly to get the most out of the weather data recorded.

Choosing a good weather station location

Location and a good setup are important for getting correct weather station data. Where possible it is recommended that you choose the site for a weather station based on professional advice from either the manufacturer, the weather station supplier, or a technical consultant.

However there are a few general guidelines that are good to follow:

• Keep away from obstructions and away from any high objects but within the area of the orchard shelter.
• Do not not expose the weather station to industrial heat sources or equipment (wind machines, pump houses, burners).
• The WMO Standard height for temperature sensors is 1.2m - 2.0m off the ground on grass.
• Ideally place the station on a grassy area not paved or stoned.
• Open ground of 5m - 10m radius around the station not under crop canopy or netting.
• Not within the range of any pivot irrigators or irrigation systems (unless you specifically want to record irrigation as rainfall on the station).

Examples of well-located weather station installations

Key weather variables and sensors

Different manufacturers may offer either modular or all-in-one weather station packages. A weather station with the following four sensors will be considered a ‘complete basic package’ and can be used with all the standard HortPlus weather and disease models.

• Anemometer
• Temperature sensor with a radiation shield (Stevenson Screen)
• Relative Humidity sensor
• Rain Gauge

Advanced sensors

A weather station with advanced sensor is able to provide more insight for certain disease risk models and tools. For example leaf wetness supersedes relative humidity data in certain tools for more accurate decision support.

Advanced sensors include:

• Leaf wetness
  Generally, the leaf wetness sensor is placed on top of the Stevenson Radiation Shield at a height between 1.25m and 2m (do not place the sensor near the ground). In the Horticultural Industry this is fixed in a northerly direction and at an angle of 10°.
• Solar Radiation (Pyranometer)
  Pyranometers should be mounted away from shadows, reflective surfaces, and sources of artificial radiation. Mount the pyranometer to minimize shading from the rest of the weather station or surrounding structures. The height the sensor is mounted is not critical for the accuracy of the measurement.
• Soil Temperature
  The measurement site for soil temperature should be typical of the surface of interest and should be at least 1m². The ground surface should be level with respect to the immediate area (10m radius).

Maintaining Your Weather Station

If a weather station is installed and maintained properly it should provide a number of years of quality data and may operate indefinitely if calibrated and sensors and parts are replaced when required. Manufacturer instructions will provide a knowledge base for maintaining your weather station, which may include managing the surrounding grass and keeping the area generally tidy, visually checking rain gauges for blockages, and ensuring free motion of an anemometer and free flow of air over the temperature sensor.

Weather Stations may need to be calibrated or repaired from time to time. Some manufacturers may suggest replacing weather station sensors after a given lifecycle or number of years within which the sensor can be considered accurate. Other manufacturers or third-party vendors may offer calibration services involving a technician inspecting and adjusting a station in person. Calibrating a station should be performed about once a year for scientific-grade or production-critical station hardware.

HortPlus performs automated data checking and validation on all station data connected to our network and our core network of HortPlus weather stations are calibrated annually.

Our automated data checks are able to give an indication when a station's data may be out of range or incorrect, however for grower-owned weather stations it is ultimately the responsibility of the station owner to ensure the station data is accurate.

Weather Station Manufacturers & Providers

The HortPlus network is hardware agnostic and can be connected to access data from a range of station manufacturers and providers.

• Harvest
• Campbell Scientific & Davis Stations (Scottech)