Blairmont Rainfall At Blairmont in Guyana, for a period of record spanning 1979 – 2014 average annual rainfall sum = 1719.2 mm wettest year on record = 2703.2 mm of rainfall in 2008 driest year on record = 979.1 mm of rainfall in 1997 wettest month on average = 245.3 mm of rainfall in June wettest …