July arrives on Sunday, the hottest month in Baltimore. The 30-year averages peak in the third week. Average highs at BWI reach 88 degrees; the lows touch 66. The city's all-time record high of 107 degrees occurred on July 10, 1936. The coolest high ever in July was 61 degrees, on July 8, 1891. And the coldest July nights sank to 50 degrees, on July 1, 1988, and July 3, 2001. One of the city's oldest standing records is for July 28 rainfall - 2.28 inches - set in 1871.