Singapore has a tropical rainforest climate (Köppen: Af ) with no distinctive seasons, uniform temperature and pressure, high humidity, and abundant rainfall. Temperatures usually range from 22 to 35 °C (72 to 95 °F). Relative humidity averages around 79% in the morning and 73% in the afternoon.[95][not in citation given] April and May are the hottest months, with the wetter monsoon season from November to January.[96] From July to October, there is often haze caused by bush fires in neighbouring Indonesia, usually from the island of Sumatra.[97] Although Singapore does not observe daylight saving time (DST), it follows the GMT+8 time zone, one hour ahead of the typical zone for its geographical location