The extreme weather events tool was produced by the eConnected Grainbelt project.
Tools & support
Extreme weather events tool
Please note: This content may be out of date and is currently under review.
The extreme weather events tool uses data from DPIRD's extensive weather station network to map air temperatures, relative humidity, dew point, Delta T and wet bulb, either below or above a specified threshold.
This can help with assessing heat and frost damage.
Information provided by the tool
This tool allows users to map areas affected by extreme weather events, using real time data from the department's weather station network. It can be used to examine events for a single day or night, or for a range of days.
Air Temperature is measured in degrees celsius and can identify when there has been a frost event (below 2°C) or a heat event (above 30°C).
Relative humidity is the ratio of how much water is in the air and how much water the air could potentially hold. Expressed as a percentage. Humid conditions can affect the growth rate of pests and disease. When conditions are too humid, it may promote the growth of mold and bacteria than cause plants to die and crops to fail, as well as conditions like root or crown rot. Humid conditions also invite the presence of pests, such as fungus gnats, whose larve feed on plant roots and thrive in moist soil.
The dew point is the temperature to which air must be cooled to become saturated with water vapour. When cooled further, the air borne water vapour will condense to form liquid water (dew). Dew point temperature is an important index of how much water is in the air. Dew point is an index used to monitor the amount of water when it is a gas in the air as water vapour. Measured in °C.
Delta T- is an important indicator for acceptable spraying conditions. It is indicative of evporation rate and droplet lifetime. Delta T is calculated by subtracting the wet bulb temperature from the dry bulb temperature. When applying pesticides, Delta T should ideally be between 2 and 8 and not greater than 10.
Wet bulb temperature is the lowest temperature to which air can be cooled by the evaporation of water into the air at a constant pressure. At 100% relative humidity the wet-bulb temperature is equal to the air temperature, at lower humidity the wet-bulb temperature is lower than dry-bulb temperature because of evaporative cooling. Wet bulb temperature is the best indicator of evaporative cooling. Irrigation should be applied before wet bulb temperature reaches a crtitical temperature.