Temperatures in Klang Valley, typically fall between 29 degrees to 35 degrees during the day and 26 degrees to 29 degrees at night. The climate in Klang Valley is quite humid all year-round. Anyone travelling to this region must always be ready for rains at any time of the year. Regardless, the best time to visit Klang Valley is from May-July or December-February.
The weather can be pretty hot between March - April. Due to the forest fires from Sumatera which typically happens between June - August, the dust particles may cast a haze over Klang Valley thus making it not an ideal time to visit the city.