Hillsborough, in California, United States, is home to roughly 11,500 people in the Pacific Time Zone at 37.6°N latitude.
In 2025, Hillsborough recorded an average annual temperature of 55°F — about 3.3°F below the 30-year normal of 59°F. The hottest day reached 91°F in September; the coldest was 37°F in January. Total precipitation was 21 inches (near normal). The wettest month was February.
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