June's average high temperature is 69.6 degrees, while September's is 70.2. September's average low temperature is also a bit higher -- 51.9 vs. 51.7 for June.
The all time September high temperature record (98, set Sept. 2, 1988) is higher than June's (96, set both June 9 and June 30 in 1956.)
Although September is a bit wetter, averaging 1.63 inches of rain versus 1.49 inches for June.
Along the same lines, October (59.7) is usually warmer than April (58.2), although October gets about a half-inch more rain than April as we start into the rainy season.