Changes in temperature and rainfall

Both maximum and minimum temperatures are expected to increase by 0.6-1.3°C, with increases fairly uniform across the year. Days above 40°C are projected to increase from 1.3 to 2.0 days annually.  Rainfall is likely to decrease by 2-24% with spring rain the most affected.

 Potential effects on crops

• Winter brassica crops may benefit from warmer temperatures but the season will be shorter
• Head lettuce development during winter may be improved
• Werribee relies on a mixture of surface, ground and recycled water for irrigation, with water quality a significant issue. From 1997-2009 rainfall was 25% below average, increasing reliance on recycled water. Projections for 2035 are that annual rainfall will decrease by 2-14%, suggesting water will continue to be a critical issue

Click HERE for a table showing the effects of changes in average temperature of +1^oC, +2^oC, +3^oC, +4^oC as well as the impact of 5 days over 35^oC for major crops grown in Werribee.

Note : These descriptions relate to the temperatures that the crops experience and not to changes in monthly average temperatures. An increase of 1^oC in monthly average temperature can easily mean increases of 4^oC or more on particular days.