Pakistan lies in a temperate zone and its climate is as varied as the country’s topography—generally dry and hot near the coast and along the lowland plains of the Indus River, and becoming progressively cooler in the northern uplands and Himalayas. Four seasons are recognized: 1) a cool, dry winter from December to February; 2) a hot, dry spring from March through May; 3) the summer rainy season, also known as the southwest monsoon period, occurring from June to September; and 4) the retreating monsoons from October to November. A majority of the country receives very little rainfall, with the exception of the Northern regions, where monsoons can bring upwards of 200 mm a month from July to September. Inter-annual rainfall varies significantly, often leading to successive patterns of floods and drought. El Niño is a significant influence on climate variability in Pakistan, with anomalies in both temperature and flood frequency and impact correlated with the El Niño cycle.