Penang enjoys a year-round equatorial climate which is warm and sunny, along with plentiful rainfall, especially during the southwest monsoon from April to September. The climate is very much dictated by the surrounding sea and the wind system. Penang's proximity with Sumatra, Indonesia makes it susceptible to dust particles carried by wind from perennial but transient forest fires, creating a phenomenon known as the haze.
The Bayan Lepas Regional Meteorological Office is the primary weather forecast facility for northern Peninsular Malaysia.
Temperature (day) 27°C-30°C
Temperature (night) 22°C-24°C
Ave annual rainfall 2670 mm
Relative humidity 70%-90%
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Average min (°C) 23.2 23.5 23.7 24.1 24.2 23.8 23.4 23.4 23.2 23.3 23.3 23.4
Average max (°C) 31.6 32.2 32.2 31.9 31.6 31.4 31.0 30.9 30.4 30.4 30.4 30.7
Lowest recorded (°C) 19 19 19 20 19 20 22 21 20 20 18 20
Highest recorded (°C) 37 36 36 37 35 36 35 35 36 34 35 35
Average rainfall (millimeters) 69 72 146 221 203 178 192 242 356 383 232 114
Ave no of days with 1 mm 5 6 9 14 14 11 12 14 18 19 15 9