California citrus growers expected an eighth consecutive night of cold temperatures Dec. 10, with some warming above critical levels forecast to start the next day.

Temperatures dipped into the low 20s for long durations Dec. 9 in the San Joaquin Valley. Growers started wind machines around 8 p.m. to prepare.

A strong inversion layer coupled with frost protection measures helped raise temperatures in the grove as high as four to five degrees in some cases, according to Exeter-based California Citrus Mutual.

The week of frigid temperatures will result in some damage for both the mandarin and navel orange crops, according to preliminary assessments by county agricultural commissioners. But the extent won’t be determined until sometime after frost conditions end.

The industry has on hand enough harvested fruit to supply the market through the holiday season without impacting consumer prices, according to a news release from the trade group. Industry representatives and government officials are developing inspection protocols to ensure damaged fruit does not enter the market place.

So far about 12% to 15% of the navel crop and 20% of mandarins have been harvested. Mandarins are at greater risk from cold.

California Citrus Mutual estimates the industry spent $28.8 million on frost protection since Dec. 3.