The climate of Pinnacles is typical of the Mediterranean climate of California, with cool wet winters and hot dry summers. Average rainfall is 16 inches per year, falling mostly from January through March. Winter climate is akin to the California deserts, with mild days and nights often dropping into the low 20s. Snow occurs in small amounts at higher elevations almost every year between mid-December and January. Summer temperatures of over 100°F are common, but coastal fog will often come into the valleys at night. Nighttime summer temperatures of 50°F are common, making for enormous daily temperature swings.
Wet and Dry Cycles
The great variability in seasonal precipitation is due to the east Pacific high. This dominant weather feature shifts northward in the summer to shunt storms far to the north. Occasionally this feature brings subtropical moisture into central California from southerly latitudes, producing one to five thundershowers per year in the Park. Mostly, however, the east Pacific high acts as a giant valve completely shutting off precipitation for long stretches of the year.
California is known for its long dry and wet cycles. Changes in the East Pacific high shift on approximately a six-year cycle. The result is persistent drought for five to eight years, followed by a wet period. Such cyclic variation is an important consideration in vegetation, wildlife, and water management.
Although the park is only 40 miles from the Pacific Ocean, the Santa Lucia Mountains to the west modify the ocean influence before it reaches Pinnacles. While on the coast summer temperatures might be a fairly steady 60 degrees Fahrenheit, at Pinnacles the temperature can swing from 50 degrees at night to 100 degrees during the day. Similarly, without the ocean’s warming effect, winter temperatures at Pinnacles often drop below freezing while coastal temperatures remain moderate.
Last updated: July 1, 2019