Protected by the Titiwangsa Mountains in the east and Indonesia's Sumatra Island in the west, Kuala Lumpur has a year-round equatorial Tropical rain forest climate (Köppen climate classification Af) which is warm and sunny, along with abundant rainfall, especially during the southwest monsoon season from September to April. Temperatures tend to remain constant. Maximums hover between 31 °C and 33 °C (88-92 °F) and have never exceeded 37 °C (99 °F), while minimums hover between 22 °C and 23.5 °C (71-74 °F) and have never fallen below 19 °C (66 °F). Kuala Lumpur typically receives 2,266 mm (89.2 in) of rain annually; June and July are relatively dry, but even then rainfall typically exceeds 125 mm (5 in) per month.