SAN DIEGO -- The National Oceanic and Atmospheric Administration announced Tuesday that San Diego temperatures have been 80 degrees or higher for 17 consecutive days, the longest streak in 34 years.
The 17-day stretch is the city's longest since a streak of 19 days in 1984, and the third-longest since such record-keeping began more than 100 years ago.
The city record is a 30-day stretch that ended on Sept. 21, 1983, according to the NOAA.
The NOAA has thus far logged 36 days of temperatures of 80 degrees or higher in 2018 in San Diego, where the average high for any month historically has not exceeded 76.4 degrees.
The main reason for the abnormally high air temperatures is the rise in ocean temperature, according to NOAA meteorologist Alexander Tardy. When ocean temperatures are closer to their usual 60s, "that air blows in on the coast and can shave off 10 to 20 degrees," he said.
As a result, ocean air blowing inland is closer to 75 degrees and the city experiences a climate similar to places like Miami, Florida, and Corpus Christi, Texas, on the Gulf Coast.
"It's as if our air conditioning isn't functioning well," Tardy said.
The NOAA uses temperature readings at the San Diego International Airport for two reasons, according to Tardy. The airport data dates to 1875, the longest-standing records available, and the airport's climate is generally cooler than parts of the city that sit further inland.
August is currently running 9.3 degrees above normal in San Diego, measured against a 30-year average from 1981 to 2010. The region is currently in its warmest period on record, with an average temperature of 76.7 degrees since July 1.