By the end of the 1990s, average temperatures in Los Angeles had risen 3 degrees fahrenheit warmer than those of the 1940s. One key factor is believed to be the dramatic loss of orchards and farmland in Los Angeles County in favor of homes, buildings and roads. The increased percentage of concrete and asphalt served to absorb more solar heat and heat up 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, average monthly temperatures overall dropped, although continuing to be higher than those in the 1940s. Since 2010, however, overall average temperatures have again climbed. According to weather data analysis by Vox.com in their 2019 article "Weather 2050", 2050 Los Angeles temperatures are projected to average 3.5 to 3.6 degrees warmer.
Temperatures in Degrees Fahrenheit.
|Decade||Average Monthly Temperature (F)||Temperature Increase Since 1880s|
* Decade only through 2018
Source: Western Regional Climate Center