December 2011 was a dry month. I recorded only two precipitation events totaling 0.75″ of rain. Only one event provided an amount that could be measured for pH. That occurred on December 12 with a pH of 4.67, which is close to the mean pH of the 2010-2011 rainy season (pH = 4.66). See the table below for the December 2011 data:
During the warm sunny days of December a thick marine haze developed that engulfed the region for many weeks (see photo above). This haze has been shown on other studies to be comprised largely of sulfate and organic aerosols, the precursors to biogenic (i.e. natural) acid rain.