Why have a weather station
A good weather station can provide extremely valuable information to allow you to monitor your heat risk.
The data your weather station collects can give a good indication of the current and past state of heat load at your site. Combine this with your site specific forecast and you now have a valuable tool to manage heat stress within your operation.
The sensors listed below are required to calculate HLI and AHLU. These sensors should be mounted at a height of approximately 2m above the surface.
Black Globe Temperature (BGT) or solar radiation and free air / dry bulb temperature
Relative humidity or wet bulb temperature
Rain (not required but can be very useful)
The above parameters need to be logged with an interval of no longer than 1 hour. Calculation of the HLI (and AHLUs) within the data logger is an advantage as immediate information will be available to assess the heat load situation in the event of a power fault or loss of internet.
Where to put your weather station
The weather station should be sited so that it is representative of the general surroundings close to the pens. Subtle variations in the environment may mean that the data are not representative. For example, a tree shadow falling across a BGT sensor will result in HLI and AHLU values that are lower than they should be for as long as that shadow is on the sensor.
Weather stations operated by the Australian Bureau of Meteorology have strict siting requirements and have to meet an Australian Standard (AS 3580.14). It is sometimes not practical to meet these standards at a particular location. In these instances, the station should ideally be located:
on a flat cleared area - either an unwatered grassy surface or one that is similar to the feedlot (not concrete)
measurements at 2m or higher above ground
no shadows should be cast on the sensors
should be located away from light-coloured walls or other objects likely to reflect sunlight
clear from obstructions such as buildings and trees (a rule of thumb is to locate the weather station at a distance from the obstruction of ten times the height of that obstruction)
The station should not be:
in a gully or other depression
on a geological formation such as a rock outcrop
on or near steep slopes, cliffs, or ridges
on a veranda or under an awning
close to a shed
surrounded by a metal fence
do NOT mount the BGT sensor on top of the logger box
located close to artificial or natural sources of moisture
If there is a solar panel, this should face north.
Weather Station Maintenance
In general equipment service should be based on supplier recommendations. Maintenance requirements vary significantly depending on the weather station configuration and technology used to measure key parameters.
Basic maintenance for all stations consists of regular inspection and keeping the components clean and free of dust and spider webs. Battery life can be prolonged by regularly inspecting and keeping the solar panel clean. Some sensors require regular recalibration. Some sensors need to be replaced periodically, every 2-5 years. In the majority of cases, sensor replacement can be undertaken by the operator.
The recommended maintenance schedule is unique to the AWS selected. The ability of the supplier to rapidly dispatch replacement sensors to your location should also be discussed as part of your Heat Management Plan.