The climate of Delhi is a
monsoon-influenced humid subtropical climate
with high variation between summer and
winter temperatures and precipitation.
Delhi's version of a humid subtropical
climate is markedly different from many
other humid subtropical cities such as Sao
Paulo, Tokyo and Brisbane in that the city
features dust storms (something more
commonly seen in a desert climate), has
relatively dry winters and has a prolonged
spell of very hot weather.
Summers start in early
April and peak in May, with average
temperatures near 32oC (90oF), although
occasional heat waves can result in highs
close to 45oC (114oF) on some days. The
monsoon starts in late June and lasts until
mid-September, with about 797.3 mm (31.5
inches) of rain. The average temperatures
are around 29oC (85oF), although they can
vary from around 25oC (78oF) on rainy days
to 32oC (90oF) during dry spells. The
monsoons recede in late September, and the
post-monsoon season continues till late
October, with average temperatures sliding
from 29oC (85oF) to 21oC (71oF).
Winter starts in November
and peaks in January, with average
temperatures around 12-13oC (54-55oF).
Although winters are generally mild, Delhi's
proximity to the Himalayas results in cold
waves that regularly dip temperatures below
freezing. Delhi is notorious for its heavy
fog during the winter season. In December,
reduced visibility leads to disruption of
road, air and rail traffic. They end in
early February, and are followed by a short
spring till the onset of the summer.