Kuantan features a tropical rainforest climate under the Köppen climate classification. Usually, Kuantan experiences two seasons per year, i.e. the "Dry" and Hot Season and also the Rainy Season. The "Dry" and Hot Season (a relative term here as the city does not truly have a dry season month) occurs when seasonal south-west winds blow from Sumatra toward the West Coast of Peninsular Malaysia but are blocked by the Titiwangsa Mountain Range. The temperature may reach 40 degrees Celsius. The Rainy Season usually occurs between October to March. During this season, the north-east winds bring rain to Kuantan. It can get very cloudy with a large amount of rainfall. Floods may also occur. Areas subject to possible flooding include the road to Sungai Lembing and also a few areas along the Kuantan River.
In 2006, Kuantan experienced significant air pollution that affected visibility because of the haze blowing in from Sumatra and the West Coast of Peninsular Malaysia