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,[60] usually accompanied by high humidity brought in by southerly winds;[56] The highest recorded temperature recorded was 115 °F (46 °C) on August 10, 1936.[61] 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.[62] The autumn season is usually short, consisting of pleasant, sunny days followed by cool nights.[60] Winter temperatures, while generally mild, dip below 10 °F (−12 °C) on 3 nights,[55] and occasionally below 0 °F (−18 °C), the most recent such occurrence being a −2 °F (−19 °C) reading on January 6, 2014.[63] Seasonal snowfall averages 9.6 inches (24.4 cm),[55] and, as of 2016, only three winters on record have officially recorded a trace or no snow, the most recent being 1910–11.[63] The lowest recorded temperature was −16 °F (−27 °C) on January 22, 1930.
[show]Climate data for Tulsa, Oklahoma (Tulsa Int'l), 1981–2010 normals, extremes 1893–present[a]