...and more
In terms of precipitation, rainfall in Penang ranges from 3.0 - 15.2 inches per month. October is typically the wettest month, when rainfall can reach 15.2 in. January is typically the driest time to visit Penang when rainfall is around 3.0 in.
If weather is an important factor for your trip to Penang, use this chart to help with planning. For those seeking warmer temperatures, January is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of August, when temperatures are typically at their lowest (around 78.8 F).