Figure 2.6: Projected changes in seasonal mean rainfall (in %), for 2040 relative to 1990: average over 12 climate models for A1B emission scenario

Text description of figure

This figure shows four seasonal maps of projected changes in seasonal mean rainfall (in percentage) over New Zealand for 2040 relative to 1990 (twelve model average) for the A1B scenario.

For summer, increases in seasonal mean rainfall of 2.5 to 5 percent are projected for the eastern North Island from East Cape down through the Wairarapa and for patches down the east coast of the South Island. Increases of up to 7.5 percent are expected for the Hawkes Bay and Gisborne. Slight decreases are projected in the west of the North Island, north-west of the South Island, and parts of Southland. Little change is seen elsewhere.

For autumn, increases in seasonal mean rainfall of 2.5 to 5 percent are projected for most places, with slight increases of 0 to 2.5 percent in Southland and Northland, Auckland and Waikato.

For winter, marked increases in seasonal mean rainfall are expected in the West with Southland and the West Coast increasing by over 10 percent, and Kapiti and Taranaki increasing by 5 to 7.5 percent. Decreases are projected in the east, with Canterbury and Hawkes Bay decreasing by more than -7.5 percent, Northland decreasing around -5 percent, and Bay of Plenty decreasing between 0 to -2.5 percent.

For spring, significant increases in seasonal mean rainfall are projected in the West with Southland and the West Coast increasing by 5 to 7.5 percent, and Kapiti and Taranaki increasing by 0 to 2.5 percent. Decreases are expected in the east, with Canterbury decreasing by 0 to -2.5 percent, Northland decreasing by around -5 percent, the Bay of Plenty decreasing by -5 to -7.5 percent, and Hawkes Bay decreasing more than -7.5 percent.