Los Angeles Rainfall Patterns Have Not Changed In 140 Years

California's recent drought was the worst drought in 1200 years. Southern California is a Semi-Arid Region, and typically receives very little rain.

Los Angeles Rainfall

The recent drought was not much different than the other droughts, low rainfall years, that have occurred in the last 140 years in the Los Angeles area. The Average Rainfall for Los Angeles is slightly less than 15 inches, but that number is Skewed Upward by the years that Los Angeles receives an extremely large amount of rain.

The rainfall in 81.6% of the last 141 years has been less than 20 inches. The 18.4% of the years that have produced more than 20 inches of rain have increased the average to a level well above the "Typical" amount of rainfall that the Los Angeles area receives.

One of the patterns that emerges from the Chart below is that every 15-25 years, Los Angeles receives less than 10 inches of rain for several years in a row, or they receive several years of less than 10 inches of rainfall, and one year of of rainfall above 10 inches. The recent 5 year Drought followed this Pattern just as the other Droughts have followed this Pattern.

Another Pattern is several years below 10 inches, and then one or two years above 15 inches. Almost one third, 29.1%, of the last 141 years have had less than 10 inches of rainfall.

The Decadal Rainfall Patterns show the same Phenomenon. Several years of Low Rainfall followed by several years of Higher Rainfall.

El Nino And La Nina

The high rainfall years are sometimes produced by an El Nino Event, but not all of the high rainfall years are caused by an El Nino Event. El Nino Years are very difficult to predict, including in the fall of the year that the conditions seem to be 'Right' for an El Nino Event. There have been years that the National Weather Service and other Weather Forecasting Services have predicted an El Nino or La Nina, but the Event did not Materialize.

The Drought years are sometimes caused by a La Nina Event, but are also caused by other phenomena. The Jet Stream being diverted North of California by a High Pressure System over Nevada, Idaho and Utah has caused many Severe Droughts, some lasting several years, in California. This type of Phenomenon has been ocurring for Thousands of Years, and is not a recent Man-Made or Human Caused Climate or Weather Event.

Claiming that the recent Drought(s) are caused by Man-Made, Human Caused Anthropogenic Climate Change is just the Politically Correct thing to say. What caused the Droughts Decades ago? What caused the Drought 80 years ago? What caused the Drought 1200 Years Ago? The Pattern of Droughts and Heavy "Recovery" Rainfall have occurred on a regular basis for the last 140 years.