At the airport, where records have been kept since 1930, the record maximum temperature was 117 °F (47 °C) on June 26, 1990, and the record minimum temperature was 16 °F (−9 °C) on January 4, 1949. There is an average of 145.0 days annually with highs of 90 °F (32 °C) or higher and an average of 16.9 days with lows reaching or below the freezing mark. Measurable precipitation falls on an average of 53 days. The wettest year was 1983 with 21.86 in (555 mm) of precipitation, and the driest year was 1953 with 5.34 in (136 mm). The most rainfall in one month was 7.93 in (201 mm) in August 1955. The most rainfall in 24 hours was 3.93 in (100 mm) on July 29, 1958. Snow at the airport averages only 1.1 in (2.8 cm) annually. The most snow received in one year was 8.3 in (21 cm) and the most snow in one month was 6.8 in (17 cm) in December 1971.
When did Tucson get the most rain in 24 hours?
July 29, 1958