Will El Niño Bring Another Year of Heavy Rain to California?

The National Weather Service recently released its Seasonal Temperature Outlook, providing a glimpse into the weather conditions expected over the next three months. According to the outlook, Southern California and the west coast can anticipate above-average temperatures during the fall and potentially the beginning of winter. Additionally, the presence of an El Niño could mean another year of heavy rainfall for the region.

While October traditionally marks the start of Santa Ana season, characterized by winds descending from mountain slopes and elevating temperatures, this year’s heat wave is expected to bring some of the hottest temperatures experienced all summer. Eric Boldt, coordinating meteorologist for the NWS’ Los Angeles branch, explains that the warming ocean and the onset of an El Niño often result in increased rainfall. Boldt notes that this El Niño event is predicted to be one of the strongest on record.

However, it is essential to consider historical data, as El Niño’s impact on California’s precipitation is not always straightforward. The NWS’ Seasonal Precipitation Outlook indicates that while the likelihood of above-average rainfall is higher, there remains a possibility of below-average precipitation. Boldt mentions the 2015 and ’16 El Niño, which was the strongest ever recorded but resulted in a dry winter for Southern California.

Interestingly, the previous California water year, spanning from October 1 to September 30, was exceptionally rainy despite occurring during a typically dry La Niña period. Downtown Los Angeles experienced its 7th rainiest year on record, receiving 128% of the average annual rainfall. With this in mind, the potential for another rain-rich year looms as El Niño takes hold.

As we await the arrival of winter, it’s important to recognize that the presence of El Niño does not guarantee a repeat of last year’s heavy rainfall. While the forecast leans towards above-average precipitation, the possibility of a dry winter cannot be disregarded. As meteorologists monitor ongoing weather patterns, predicting the exact outcomes remains a challenge.


What is El Niño?

El Niño refers to a climate pattern that occurs in the Pacific Ocean, characterized by warmer-than-average sea surface temperatures in the central and eastern regions. It can have a significant impact on global weather patterns, leading to increased rainfall in some areas and droughts in others.

What is the National Weather Service (NWS)?

The National Weather Service is a government agency responsible for providing weather forecasts, warnings, and climate-related information to the public.

What is the water year in California?

The water year in California spans from October 1 to September 30. It is a period used to track and evaluate the state’s annual precipitation and water supply.

How does El Niño affect California’s rainfall?

During an El Niño event, California can experience above-average precipitation due to changes in atmospheric circulation patterns. However, the impact of El Niño on rainfall can vary, and it is not always a guarantee of increased rainfall.