Spring frosts occasionally cause drastic reductions in crop yield and quality in localised parts of the Western Australian grainbelt. Frost occurs on clear nights in early spring when the air temperature drops to 2°C or less. The amount of damage to crops from frost is influenced by:
- the absolute minimum temperature (frost event severity)
- how long the temperature remains low (event duration)
- the growth stage of the crop (frost causes most damage at and around flowering)
- local topography (low-lying areas are more susceptible).
Heat stress is caused by high temperatures and hot dry winds before or during flowering.
This tool allows users to map areas affected by frost or heat stress events, using real time data from DAFWA's weather station network. It can be used to examine events for a single day or night, or for a range of days. The period of time considered can be chosen as:
- Calendar day (00:00 to 24:00)
- Night (09:00 yesterday to 9:00) - useful when considering low temperature/frost events
- Day (09:00 to 09:00 the next day) - useful for considering high temperature/heat stress events.
The user can then select the mode and temperature threshold to examine cold or hot events of varying severity.