Avalon Hester, Valley News Intern
Hurricane Hilary, which started out as a powerful Category 4 storm, made historic landfall last weekend as a tropical storm. While you were busy collecting sandbags, keeping your pets safe indoors, and securing loose items, you might have been wondering, when was the last time a storm of this magnitude hit Southern California?
According to the National Weather Service, the last time a hurricane came through Southern California was 165 years ago – the San Diego Hurricane of October 2nd, 1858. That historic storm grounded ships and battered San Diego County with 75 mph winds for several hours.
Storms of this nature are exceedingly rare in this area; it’s been 84 years since San Diego
County experienced even the slightly lesser threat of a tropical storm.
The National Weather Service reported that the last and only known tropical storm to hit San Diego County occurred in 1939, and resulted in $2 million worth of damages (~$43 million in today’s dollars.).
According to the National Oceanic and Atmospheric Administration (NOAA) the difference between a hurricane and a tropical storm is wind speed, with a hurricane being any storm with winds above 74 mph and a tropical storm having wind speeds between 33mph and 73 mph.
One of the reasons that hurricanes and tropical storms have been so unlikely to affect
Southern Californians is the cool water temperatures along the Pacific Coast. The National
Weather Service states that “Water temps need to be at least 80 degrees for hurricanes to sustain themselves.” The water temperature in California varies between 55 degrees and 75 degrees, according to Orange County Lifeguards. This means that hurricanes are usually calmed before making landfall in SoCal.
Hurricane Hillary was downgraded to a tropical storm as it reached cooler waters outside of Mexico. The NOAA measured the water temperature off San Diego Bay at 71.8 degrees early Friday morning – which helped lessen the categories and slow the storm as it made landfall.