Method
Hot Days
Fruit crops have critical upper temperature limits for growth and fruit quality. At air temperature > 35°C, many physiological processes (e.g. photosynthesis) decline, certain metabolites (e.g. red pigment) begin to be destroyed, and tissue damage (e.g. sunburn) can occur.
The number of days per annum when the maximum air temperature exceeds 35°C was calculated from daily temperature data. More detail is provided in the section Background: Climate Change Modelling.
The modelling for the intermediate future (2050s) was conducted using five different CMIP3 GCMs (Schulze, 2011).
Maps
Map Information
The Klein Karoo (West) has a historical annual occurrence of hot days ranging widely between 2 (Koo) and 16 (Montagu) days. Climate model projections for the intermediate future (mid-century) show an increase of around 2-8 days per annum (but higher east of Barrydale).