Temperatures across the San Joaquin Valley were manageable, ranging in the upper 20s and low 30s in most areas. Growers report running wind machines periodically throughout the night to elevate grove temperatures. Some growers also report running water during the day to prepare the ground for colder overnight temperatures. The combination of warm air rising from the moist ground and the circulation of that air by wind machines can raise grove temperatures by 3-5 degrees.
Growers will typically start running wind machines on Mandarin varieties when temperatures fall to freezing. Orange and lemon varieties tend to be more cold tolerant, and can withstand temperatures as low as 28 degrees.
he critical factor is duration when temperatures dip below freezing. Short periods of temperatures in the upper 20s and low 30s can be ideal for most citrus varieties.
Overall, Valley citrus growers dodged a hard freeze for a second night in a row.