Climate of Delhi

Delhi features a humid subtropical climate (Köppen Cwa), closely bordering a hot semi-arid climate (Köppen BSh). This features hot summers accompanied by frequent thunderstorms locally known as andhi, and cool winters that are characterized by dense fog. The city's rainfall pattern is heavily influenced by the summer monsoon entering in late June and continuing till mid-September, and western disturbances occurring from November to March.

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) 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. Winter generally ends by the first week of March.

Extreme temperatures have ranged from −2.2 to 49.9 °C (28.0 to 121.8 °F).