 On average , May is the wettest month , averaging 5 @.@ 9 inches of rainfall . Triple @-@ digit temperatures ( ≥ 38 ° C ) are observed on average 11 days per year , sometimes exceeding 105 ° F ( 41 ° C ) from July to early September , usually accompanied by high humidity brought in by southerly winds ; The highest recorded temperature recorded was 115 ° F ( 46 ° C ) on August 10 , 1936 . Lack of air circulation due to heat and humidity during the summer months leads to higher concentrations of ozone , prompting the city to release " Ozone Alerts " , encouraging all parties to do their part in complying with the Clean Air Act and United States Environmental Protection Agency standards . The autumn season is usually short , consisting of pleasant , sunny days followed by cool nights . Winter temperatures , while generally mild , dip below 10 ° F ( − 12 ° C ) on 3 nights , and occasionally below 0 ° F ( − 18 ° C ) , the most recent such occurrence being a − 2 ° F ( − 19 ° C ) reading on January 6 , 2014 . Seasonal snowfall averages 9 @.@ 6 inches ( 24 @.@ 4 cm ) , and , as of 2016 , only three winters on record have officially recorded a trace or no snow , the most recent being 1910 – 11 . The lowest recorded temperature was − 16 ° F ( − 27 ° C ) on January 22 , 1930 . 
