Last month's noticeable coolness in Southern California (at least, in the mornings and evenings) was apparently the tail-end of a rare, not-made-up climate phenomenon called "reverse" spring—so not-made-up that the National Weather Service's data suggests that LA just had one. The "reverse" part refers to "average monthly temperatures [that] decrease instead of increase" between March and May, says KPCC, and it's only the third time this has happened since record-keeping began in 1877.
Usually, May is the hottest month of spring and March is the coolest (duh). This year, though, it was the other way around. The monthly average temperature in Downtown was 68.2 degrees in March, then 65.8 in April, and 64.2 degrees in May. For comparison, 30-year average temperatures for those same months are 60.6 degrees (March), 63.1 degrees (April), and 65.8 degrees (May). The spring has been warmer and drier than normal in DTLA and across southwestern California overall, says a posting from the agency.
An NWS rep calls the backwards spring "kind of a continuation of our strange weather we've had over the last couple of years," where winters have been unnervingly warm. Before this year, "reverse" springs had only been recorded in 1914 and 1921.
· Southern California just had its first 'reverse' spring in nearly 100 years [SCPR]
· Could SoCal's Cool May Become a Drought-Relieving Winter? [Curbed LA]
· Los Angeles vs. Boston: Extreme Winter Weather Comparison [Curbed LA]