How Hot/Cold?

Assess the chance of heat-stress and cold-stress events for any day of the year.

Cold & heat stress

How hot-cold? allows you to visualise heat and cold stress patterns througout the year to help visualise potential sowing windows and flowering times. It estimatest the risk of daily maximum temperature exceeding a specified heat stress value and the daily minimum temperature being less than a specified cold stress value. It provides outputs showing the period of the year when both heat and cold stress are less than a specified probability of occurrence. This information aids in the decision of when to plant to avoid heat and cold stress.

It is designed for decision makers who need to assess the balance between heat and cold stress for any time of the year. Crop flowering is the most common issue that challenges farmers who must flowering to avoid frost risk at the end of a winter season and avoiding a fast approaching heat stress period. Specifically, it provides outputs showing:

  • When is the best time for a crop to be flowering, based on avoiding both heat and cold or frost stress?
  • When will the minimum temperature exceed a threshold for successful crop establishment?


  • Location
  • A specified date for risk-assessment
  • Heat and cold stress threshold temperatures
  • An acceptable risk probability


Text and graphical presentations are provided:

  • The current risk of heat and cold stresses
  • line graph showing the probability of heat and cold stress for each day of the year.


The CliMate version of How Hot –Cold? was based on the CropMate analysis developed by New South Wales Department of Primary Industries and adapted to the iOS Smart Phone software by RPS Australia East and DHM Environmental Software Engineering Pty Ltd for the Managing CliMate Variability Research and Development Program.