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The Warming of Los Angeles

Red Downtown Los Angeles Skyline. Photo courtesy of Tpsdave & Pixabay.com.

By the end of the 1990s, average temperatures in Los Angeles had risen to more than 3 degrees Fahrenheit warmer than in the 1940s. This was believed to be due to the dramatic loss of Los Angeles County orchards and farmland in favor of buildings and roads. The increased concrete and asphalt served to absorb more solar heat and heat up the surrounding atmosphere, causing a massive "urban heat island." Studies suggest that a massive planting of trees in the San Fernando Valley alone might lower average temperatures as much as 9 degrees. After the 1990s, there was a drop in average monthly temperatures, although these continued to be higher than those in the 1940s and have again continued to climb.

Average Monthly Temperatures by Decade
Downtown Los Angeles, 1880s - 2010s

Temperatures are in Degrees Fahrenheit.

Decade Average Monthly Temperature (F) During Decade Temperature Increase Over 1880s
2010-2018* 66.6 +3.9
2000-2009 65.4 +2.7
1990-1999 67.0 +4.3
1980-1989 67.3 +4.6
1970-1979 65.3 +2.6
1960-1969 65.1 +2.4
1950-1959 64.9 +2.2
1940-1949 63.6 +0.9
1930-1939 64.5 +1.8
1920-1929 63.6 +0.9
1910-1919 62.4 -0.3
1900-1909 62.2 -0.5
1890-1889 62.1 -0.6
1880-1889 62.7 0.0

* Decade only through 2018

Source: Western Regional Climate Center


Also see: High/Low & Average Temperatures by Month & Year for Downtown Los Angeles.