Topzle Updated: Wikipedia source
Altadena (AL-tə-DEE-nə) is an unincorporated area, and census-designated place in the San Gabriel Valley and the Verdugos regions of Los Angeles County, California. Directly north of Pasadena, it is located approximately 14 miles (23 km) from Downtown Los Angeles. Its population was 42,846 at the 2020 census, up slightly from a 2010 figure of 42,777. In early 2025, the community was severely impacted by the Eaton Fire.
| Climate data for Altadena, California (1991-2020 averages, 1922-2016 extremes) | |||||||||||||
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °F (°C) | 93(34) | 92(33) | 98(37) | 105(41) | 104(40) | 113(45) | 110(43) | 107(42) | 111(44) | 108(42) | 101(38) | 93(34) | 113(45) |
| Mean daily maximum °F (°C) | 64.3(17.9) | 64.4(18.0) | 66.6(19.2) | 67.0(19.4) | 75.0(23.9) | 79.1(26.2) | 85.8(29.9) | 86.8(30.4) | 84.6(29.2) | 76.9(24.9) | 72.8(22.7) | 65.8(18.8) | 74.1(23.4) |
| Mean daily minimum °F (°C) | 42.3(5.7) | 43.9(6.6) | 44.8(7.1) | 45.9(7.7) | 50.2(10.1) | 52.9(11.6) | 57.7(14.3) | 59.1(15.1) | 58.4(14.7) | 51.8(11.0) | 48.5(9.2) | 44.6(7.0) | 50.0(10.0) |
| Record low °F (°C) | 21(−6) | 26(−3) | 29(−2) | 31(−1) | 32(0) | 41(5) | 45(7) | 43(6) | 41(5) | 36(2) | 26(−3) | 25(−4) | 21(−6) |
| Average rainfall inches (mm) | 4.80(122) | 5.74(146) | 3.19(81) | 1.29(33) | 0.74(19) | 0.21(5.3) | 0.08(2.0) | 0.01(0.25) | 0.18(4.6) | 0.91(23) | 1.18(30) | 3.04(77) | 21.37(543.15) |
| Average rainy days (≥ 0.01 inch) | 6.4 | 6.0 | 4.9 | 2.9 | 2.4 | 0.8 | 0.2 | 0.2 | 0.7 | 2.4 | 2.4 | 4.9 | 34.2 |
| Source 1: WRCC | |||||||||||||
| Source 2: WRCC | |||||||||||||
| Race / Ethnicity (NH = Non-Hispanic) | Pop 2000 | Pop 2010 | Pop 2020 | % 2000 | % 2010 | % 2020 |
| White alone (NH) | 16,848 | 17,231 | 17,900 | 39.54% | 40.28% | 41.78% |
| Black or African American alone (NH) | 13,112 | 9,816 | 7,136 | 30.77% | 22.95% | 16.65% |
| Native American or Alaska Native alone (NH) | 117 | 85 | 46 | 0.27% | 0.20% | 0.11% |
| Asian alone (NH) | 1,761 | 2,231 | 2,919 | 4.13% | 5.22% | 6.81% |
| Native Hawaiian or Pacific Islander alone (NH) | 49 | 65 | 47 | 0.11% | 0.15% | 0.11% |
| Other race alone (NH) | 151 | 187 | 293 | 0.35% | 0.44% | 0.68% |
| Mixed race or Multiracial (NH) | 1,882 | 1,660 | 2,334 | 4.42% | 3.88% | 5.45% |
| Hispanic or Latino (any race) | 8,690 | 11,502 | 12,171 | 20.39% | 26.89% | 28.41% |
| Total | 42,610 | 42,777 | 42,846 | 100.00% | 100.00% | 100.00% |