Government of Bihar

Hon'ble Chief Minister of Bihar
Shri Samrat Choudhary Hon'ble Chief Minister
Government of Bihar | Official Website

Soil and Climate of Bihar

🌱 Soil

Soil is one of the most important resources of a nation. It is the gift of nature of immense value. The most common use of the word soil is in the sense of a medium in which plants grow. Almost all the economic activities are directly or indirectly dependent on soil. Thus soil is the backbone of agricultural and industrial development.

The Bihar plane consists of a thick alluvial mantle of drift origin overlying in most part the Siwalik and older tertiary rocks. The soil is mainly young loam rejuvenated every year by constant deposition of silt, clay and sand brought by different streams. This soil is deficient in phosphoric acid, nitrogen and humus, but potash and lime are usually present in sufficient quantity.

Three Major Types of Soil in Bihar
  • Piedmont Swamp Soil – found in northwestern part of West Champaran district.
  • Terai Soil – found in northern part of the state along the border of Nepal.
  • The Gangetic Alluvium – the plain of Bihar is covered by Gangetic alluvium (both new as well as old).

☀️ Climate

The climate of Bihar is a part of the climatic pattern of the Indian subcontinent. It enjoys a continental monsoon type of climate owing to its great distance from the sea.

Factors Affecting the Climate of Bihar
  • It extends from 22° North to 27° North latitude. Hence its location is tropical to sub-tropical.
  • The Himalayan Mountains in the north have a significant bearing on the distribution of monsoon rainfall in Bihar.
  • Bihar joins the Ganga delta and Assam.
Climate Overview
Classification Cwa
Avg. Temperature 27 °C (81 °F)
Summer 34 °C (93 °F)
Winter 10 °C (50 °F)
Precipitation 975.86 mm (Source: IMD)

🌡️ Seasons and their Duration

❄️ Winter

The cold weather commences early in November and comes to an end in the middle of March. The climate in October and November is pleasant. The days are bright and warm and the sun is not too hot. As soon as the sun sets the temperature falls and the heat of the day yields place to a sharp bracing cold.

Temperature in Winter: 0–10 °C
Coldest months: December and January
Record low: 0 °C in Gopalganj, -2 °C in Forbesganj

☀️ Summer

The hot weather sets in March and lasts until the middle of June. The highest temperature is often registered in May which is the hottest month in the state. Like the rest of northern India, Bihar also experiences dust-storms, thunder-storms and dust-raising winds during the hot season.

Dust storms having a velocity of 48–64 km/hour are most frequent in May. The hot winds (loo) blow during April and May with an average velocity of 8–16 km/hour.

🌧️ Monsoon

Soon after mid-June the rainy season commences and continues till the end of September. The beginning of this season occurs when a storm from the Bay of Bengal passes over Bihar. The rainiest months are July and August. The rains are the gifts of the south-west monsoon. The south-west monsoon normally withdraws from Bihar in the first week of October.

🍂 Post Monsoon

An important feature of the retreating monsoon season in Bihar is the invasion of tropical cyclones originating in the Bay of Bengal at about 12° N latitude. Bihar is also influenced by the typhoons originating in the south China sea. The maximum frequency of the tropical cyclones in Bihar is during September–November especially during the asterism called Hathiya.

These cyclones are essential for the maturing of paddy, and are required for the moistening of the soil for the cultivation of Rabi crops.