 Tiruchirappalli experiences a tropical savanna climate — designated "Aw" under the Köppen climate classification — with no major change in temperature between summer and winter. The climate is generally characterised by high temperature and low humidity. With an annual mean temperature of 28.9°C (84.0°F) and monthly average temperatures ranging between 25°C (77°F) and 32°C (90°F), the city is the hottest in the state. The warmest months are from April to June, when the city experiences frequent dust storms. As of November 2013, the highest temperature ever recorded in Tiruchirappalli was 43.9°C (111.0°F), which occurred on 2 May 1896; the lowest was observed on 6 February 1884 at 13.9°C (57.0°F). The high temperatures in the city have been attributed to the presence of two rivers — Kaveri and Kollidam — and the absence of greenery around the city. As Tiruchirappalli is on the Deccan Plateau the days are extremely warm and dry; evenings are cooler because of cold winds that blow from the south-east. From June to September, the city experiences a moderate climate tempered by heavy rain and thundershowers. Rainfall is heaviest between October and December because of the north-east monsoon winds, and from December to February the climate is cool and moist. The average annual rainfall is 841.9 mm (33.15 in), slightly lower than the state's average of 945 mm (37.2 in). Fog and dew are rare and occur only during the winter season.
