Pakistan is in the warm Temperate Zone with general aridity, hot summers, and cool or cold winters. The winds in winter blow Northeast to Southwest and reverse in summer to bring the monsoon. The cold-weather season from December through February is characterised by somewhat low temperatures. Some precipitation sweeps across Iran and Afghanistan into Pakistan from small low-pressure disturbances that form along the Mediterranean front. This heat causes progressively lower pressures that pull the monsoon winds and rain from the Indian Ocean in June through September.
Temperatures decrease, but the humidity increases so that it feels little different.
In October and November the high pressures and cooler temperatures re-establish themselves to produce a comfortable autumn. Forests, shrubs, and grasses are grouped into three main divisions. The Saharo-Sindian flora is predominantly tropical or subtropical and is as diverse as mangrove coastal swamps, desert and savannah scrubs, and seasonally flooded aquatic or semiaquatic species. The Irano-Turanian floras are discontinuous areas of semiarid open shrublands and such forests as the pencil junipers, pistachio, ash, and Chilghoza pines of Baluchistan. This floral type extends well into the dry mountain valleys of the Himalayas and includes spruce, willow, and other woody species.