The Weather Project · Orchards & winter chill
Chill-hour forecasts for Australian orchards
See how much additional chill is forecast over the coming days. Put the short-term outlook alongside your orchard records when planning dormancy monitoring and seasonal work.
Understand the product
Read the accumulation period first
Chill hours are shown in hours. Each map totals the modelled chill contribution across its forecast window. A five-day and a ten-day map cover different periods, so their totals should not be compared as though they represent the same window. Read the model run, lead and valid-to time.
Use forecast chill alongside orchard records
The outlook can help orchard managers anticipate whether the next few days add little or substantial chill. It complements observed seasonal records; it does not replace them. Keep a consistent chill method and season start when comparing your own records with crop requirements.
Forecast chill is not a dormancy diagnosis
Varieties differ in their chill requirements, and crop responses depend on the accumulation method and subsequent warmth. These maps should not be read as a declaration that a variety has met its requirement or will flower on a particular date.
Chill hours are not interchangeable with chill portions
Different chill models count temperature exposure differently. This product is labelled chill hours; it is not a Dynamic Model chill-portions product. Check that any cultivar target uses a compatible method before interpreting a total.
See what the maps look like
Examples illustrate the format and legend. They are not a live forecast briefing; use the forecast viewer for the latest available run and valid time. Select an image to open it at full size.
From the map to your site
Open the forecast viewer, choose your region and product, then read the model run and local valid date. Compare related maps over matching periods and check local observations before making a time-sensitive decision. Longer-range forecasts are best used for planning and reassessed as the date approaches.
Common questions
Is the map a season-to-date total?
No. It shows forecast accumulation over the window printed on the map. Use your observed seasonal record for winter-to-date accumulation.
Why might a spring map show very little chill?
If few forecast hours satisfy the product’s chill criteria, the additional accumulation can be small. A low future total does not erase chill accumulated earlier in the season.
Independent model guidance from The Weather Project. Check the map’s method, coverage and valid period. Regional guidance complements local measurements and crop-specific advice.