The city is located on a vast plain bisected by the River Tigris. The Tigris splits Baghdad in half, with the eastern half being called 'Risafa' and the Western half known as 'Karkh'. The land on which the city is built is almost entirely flat and low-lying, being of alluvial origin due to the periodic large floods which have occurred on the river.
Baghdad has a subtropical arid climate (K�ppen climate classification BWh) and is, in terms of maximum temperatures, one of the hottest cities in the world. In the summer from June to August, the average maximum temperature is as high as 44 �C (111 �F) accompanied by blazing sunshine: rainfall has in fact been recorded on fewer than half a dozen occasions at this time of year and has never exceeded 1 millimetre (0.04 in). Temperatures exceeding 50 �C (122 �F) in the shade are by no means unheard of, and even at night temperatures in summer are seldom below 24 �C (75 �F). Because the humidity is very low (usually under 10%) due to Baghdad's distance from the marshy Persian Gulf, dust storms from the deserts to the west are a normal occurrence during the summer.
Winters boast mild days and variable nights. From December to February, Baghdad has maximum temperatures averaging 15.5 to 18.5 �C (60 to 65 �F), though highs above 70 �F (21 �C) are not unheard of. Morning temperatures can be chilly: the average January low is 3.8 �C (38.8 �F) but lows below freezing only occur a couple of times per year.
Annual rainfall, almost entirely confined to the period from November to March, averages around 150 mm (5.91 in), but has been as high as 338 mm (13.31 in) and as low as 37 mm (1.46 in). On January 11, 2008, light snow fell across Baghdad for the first time in memory
