Cool weather means California Pinot Noir growers may harvest far less than expected.

Rains in May and a foggy summer in northern coastal areas halved farmers' original forecasts. Rains occurred when Pinot Noir was blooming, damaging young clusters, and mildew and fungus are causing farmers to use more fungicides than usual.

However, smaller crops may lead to better wines if the weather stays dry. With decreased supply, higher prices seem inevitable, especially if quality improves.

Pinot Noir has been America's hottest variety since the 2004 film "Sideways," with sales up 42.8% in US supermarkets last year. Other Pinot regions were not as hard hit as Sonoma, with many Monterey growers expecting above-average crops.