The weather in Petrolia is temperate. The town is located in a banana belt that is sheltered from the fog that reaches Eureka and some of the northern towns, such as Arcata and McKinleyville. As a result, the summers are dry and sunny, typically around with temperatures occasionally reaching as high as . Winters are rainy from November through April, with temperatures typically around and occasionally falling to the high 30's or low 40s (F) at night. Honeydew, which is located only south of Petrolia, has a less temperate climate and its summers and winters are more extreme, with one of the highest amounts of winter rainfall in the contiguous 48 states.