Delhi features a hot semi-arid climate (Köppen BSh) bordering a humid subtropical climate (Köppen Cwa), with high variation between summer and winter temperatures and precipitation.[1]
Summer starts in early April and peaks in late May or early June, with average temperatures near 38 °C (100 °F) although occasional heat waves can result in highs close to 45 °C (113 °F) on some days and therefore higher apparent temperature. The monsoon starts in late June and lasts until mid-September, with about 797.3 mm (31.39 inches)[2] of rain. The average temperatures are around 29 °C (84 °F), although they can vary from around 25 °C (77 °F) on rainy days to 35–40 °C (95–104 °F) during dry spells. The monsoons recede in late September, and the post-monsoon season continues till late October, with average temperatures sliding from 29 to 21 °C (84 to 70 °F).
Winter starts in November and peaks in January, with average temperatures around 14 °C (57 °F). Although daytime temperatures are warm, Delhi’s proximity to the Himalayas results in cold waves leading to lower apparent temperature due to wind chill. Delhi experiences heavy fog and haze during the winter season. In December, reduced visibility leads to disruption of road, air and rail traffic.[3] Winter generally ends by the first week of March.