CLIMATE
Munger district is a part of Zone – III with sub-zone in South Bihar Plains. The zone is located on south of river Ganges and comprises districts of Munger, Bhagalpur, Gaya, Aurangabad, Rothas, Bhojpur, Patna and Nalanda. It is sub humid and much drier as compared to zone-I and III. It has monsoon sub-tropical climate ranging from sub-dry and sub-humid conditions. There are three district seasons in this zone viz., summer, monsoon and winter.
SUMMER (MARCH TO MAY)
The summer season is characterized by gradual rise in temperature, occasional thunder showers and hail storm, high velocity westerly during this season is very dry resulting in sunstroke deaths at times. The maximum temperature rises up to 45o C.
MONSOON (JUNE TO SEPTEMBER)
It starts from middle of June and continues up to end of September. Monsoon is characterized by cloudy weather, high humidity, frequent rains and weak variable surface wind. Maximum rainfall occurs during July and August.
WINTER (OCTOBER TO FEBRUARY)
Winter season is characterized by gradual decrease in temperature which comes to a minimum in the first week of January. Thereafter, the temperature starts increasing. The minimum temperature varies from 3.50 C to 90 C.
RAINFALL
The rainfall under this zone is mainly influenced by the south-west monsoon which sets in the second week of June and continues up to end of September. Sometimes cyclonic rain also occurs. The average annual rainfall of this zone is 1078.7 mm. The rainfall distribution is marked seasonal in character. Greatly limiting water availability in certain times of the year and requiring disposal of excess water in some weeks during monsoon also occur. The average annual rainfall of Munger district is 1146.4mm (53year average), out of which 80% is received during monsoon season and the rest (more than5%)in summer season. In case of Munger district, the temporal variation annual rainfall was recorded at a maximum of 2181.6 mm in 1971 and a minimum of 481.6 mm in 1972 with annual coefficient of variation of 27.2%. July and August received maximum monthly rainfall in the district. The monthly co-efficient of variation of rainfall for monsoon from June to September was 68.5%, 44.3% and 51.8% respectively for Munger.