PLYMOUTH, Mass. — With summer winding down, the cranberry bog harvest can’t be far behind.

The head of the Cape Cod Cranberry Growers’ Association, Brian Wick, said his members are largely optimistic about this year’s crop, but weather remains a variable.

The USDA’s National Agricultural Statistics Service forecasts the total U.S. cranberry crop to hit 9 million barrels, a 4 percent increase over 2018. One barrel equals 100 pounds of cranberries.

In Massachusetts, the second largest cranberry producer behind Wisconsin, the crop is projected at 2.3 million barrels, up about 3 percent from last year.

Wick said early September is a critical period for cranberries, which need both additional moisture and cooler nights to reach full size and develop their distinctive color.

While most growers deploy supplemental irrigation systems, he said “nothing beats a good soaking rain.”