About Hilmar Irwin, CA's Climate & Weather History

Hilmar Irwin is a city of approximately 5,200 people in California, United States. Located in the Pacific Time Zone at 37.4°N latitude.

In 2025, Hilmar Irwin recorded an average annual temperature of 64°F — about 4.3°F above the 30-year normal of 60°F. The hottest day reached 107°F in May; the coldest was 30°F in January. Total precipitation was 19 inches (wetter than usual). The wettest month was November.