(KGW) - Heavy rains may make for a soggy harvest in Oregon's wine country.

In the southern Willamette Valley, for instance, the Eugene Register-Guard reports that with heavy precipitation the past two weeks, September rainfall is more than four times the local average. That threatens grapes with mildew, rot, dilution and splitting.

Cold days and nights shut some vines down for the winter, causing leaves to turn orange and vines to begin leaching sugars from the grapes.

The conditions are especially tough on Oregon's prize but finicky pinot noir grapes.

It may be weeks or months, though, before winemakers can assess the impact of the rain on this year's wines.