La Nina, the weather cycle characterised by wet conditions, cooler days and warmer nights, will peak this summer, bringing cyclone season with it, although it will be weaker than the very strong La Nina last year.

Despite a string of rainy summers since 2007, Sydney summers are not getting wetter. ''They're just the ones that stick in your mind,'' Ms Pepler said.

And the dreariness isn't confined to the skies. The usual summertime jobs boom will be muted and spending will be less-than-sunny.

Christmas spending is expected to rise 3.3 per cent from last year, with the average shopper spending $1213 over December, but inflation means most retailers will simply be treading water, said Karen Dobbie, general manager of the market researcher IBISWorld.

About 40,000 casual retail jobs will be created to meet demand in NSW, according to the National Retail Association. But with retail and tourism looking gloomy, ''job numbers are going to be a bit disappointing compared to previous years,'' said Michael Emerson, a economist and employment forecaster.