6 degrees Celsius) cooler than it is inland during summer days, and 5 to 10 degrees warmer during winter nights. It is also in September that the highest temperatures tend to be reached. It is winter, however, when the hot, dry winds of the Santa Anas are most common. In contrast, temperatures exceeding 10 degrees below average are rare. The rainy season is from late October through late March. Winter storms usually approach from the northwest and pass quickly through the Southland. There is very little rain during the rest of the year. Yearly rainfall totals are unpredictable as rainy years are occasionally followed by droughts. There has never been any snow or frost, but there has been hail. Santa Monica usually enjoys cool breezes blowing in from the ocean, which tend to keep the air fresh and clean. Therefore, smog is less of a problem for Santa Monica than elsewhere around Los Angeles. However, from September through November, the Santa Ana winds sometimes blow from the east, bringing smoggy and hot inland air to the beaches. The hottest temperature ever reported in Santa Monica was on November 1, 1966, while the lowest is on March 1, 1945, and again on March 21, 1952. The highest minimum temperature is on October 24, 2007, and the lowest maximum temperature is on 4 dates in February 2001 and again March 10, 2006. The snowiest months on record are January 1954 and March 1955, both with trace amounts. They are the only months to ever report snowfall. Many months have reported no rainfall at all. Conversely, the wettest month on record is January 1995 with a total of of rainfall. The wettest year on record is 1998, with a total of of rainfall; the driest is 1989, with a total of of rainfall. Environment The city first proposed its Sustainable City Plan in 1992 and in 1994, was one of the first cities in the nation to formally adopt a comprehensive sustainability plan, setting waste reduction and water conservation policies for both public and private sector through its Office of Sustainability and the Environment. Eighty-two percent of the city's public works vehicles run on alternative fuels, including most of the municipal bus system, making it among the largest such fleets in the country. Santa Monica fleet vehicles and buses source their natural gas from Redeem, a Southern California-based supplier of renewable and sustainable