94513 is part of Ecoregion. 94513 averages 61 - 90 days per year where the temperatue exceeds 86°F. The average annual high temperature in 94513 is 73°F and the average annual low temperature is 48°F.The average high temperature in July (Summer) is 89°F, while the average high temperature in January (Winter) is 54°F.ip code 94513, Brentwood CA is in USDA Hardiness Zone 9b: 25F to 30F. Using updated climate data through 2010, 94513 is in the Plantmaps Hardiness Zone 9a: 20F to 25F. The average first frost in 94513 is between November 21 - 31, while the average last frost occurs between February 21 - 28.