The District Darrang is situated at the center of the state, which comes under North Bank Plain Zone (NBPZ) of Assam, occupies a geographical area of 1850.58 sq. km between longitudes 20o09'N to 26o95'N and latitudes 91o45'E to 92o22'E.The district is surrounded in the north by Udalguri District, in the east Sonitpur District and in the west by Kamrup District. The major physiographic variation of the district is in general considered to be plain except high land areas, flood prone areas, char lands and swampy areas. The mighty Brahmaputra flows along the southern periphery of the district. Thus, the district is also well connected with the water ways. The river Brahmaputra is the main river in the border of the south of the district flows from the east to west direction. Other important tributaries of the Brahmaputra are Barnadi, Nanoi, Mangaldai, Nowanodi, Saktola, Dhansiri,which are the main River flowing through the district and the rivers are perennial in nature.
The climate of the district is congenial. In the winter, the northern part of the district is colder than the rest of the district The average temperature ranges from 10o to 30o C. Average annual rainfall is about 1791 mm. The relative humidity is about 37% in the month of February/ March and about 82% in other months. The monsoon of the district commences from the end of March and intensity gradually increases up to August and then declines to the minimum during November and December. The rainfall of the district is given below in table
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| Month | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| January | 31.8 | 0.0 | 17.2 | 34.6 | 0.0 | 0.0 | 25.2 | 0.0 | 0.0 | 4.0 | 19.6 |
| February | 0.0 | 60.4 | 2.2 | 13.4 | 30.6 | 125.4 | 17.6 | 2.2 | 0.0 | 8.0 | 0.0 |
| March | 80.6 | 40.4 | 44.0 | 141.1 | 2.2 | 13.8 | 106.9 | 59.4 | 148.4 | 126.2 | 18.4 |
| April | 144.8 | 223.4 | 267.8 | 333.0 | 146.0 | 562.6 | 220.3 | 170.2 | 315.4 | 82.5 | 458.6 |
| May | 253.0 | 311.2 | 283.0 | 129.6 | 102.4 | 223.6 | 204.8 | 293.9 | 287.2 | 236.4 | 181.7 |
| June | 259.8 | 205.0 | 174.0 | 234.4 | 225.8 | 323.0 | 397.2 | 154.9 | 560.9 | 264.0 | 610.2 |
| July | 265.2 | 189.2 | 527.0 | 223.8 | 107.4 | 445.8 | 422.2 | 361.8 | 480.4 | 327.2 | 109.2 |
| August | 172.4 | 217.4 | 128.4 | 599.2 | 201.6 | 219.6 | 130.0 | 236.6 | 217.9 | 367.9 | 133.2 |
| September | 59.6 | 229.4 | 103.9 | 84.4 | 76.6 | 456.8 | 159.8 | 29.5 | 205.3 | 233.1 | 184.8 |
| October | 3.2 | 212.0 | 151.2 | 122.8 | 93.0 | 138.4 | 23.4 | 150.0 | 113.4 | 70.0 | 112.7 |
| November | 13.8 | 0.0 | 11.2 | 0.0 | 29.0 | 19.4 | 0.0 | 4.0 | 0.0 | 1.4 | 0.0 |
| December | 0.0 | 0.0 | 0.0 | 0.0 | 11.4 | 0.0 | 0.0 | 0.0 | 1.0 | 0.0 | 0.0 |
| Month | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| January | 1 | 0 | 5 | 3 | 0 | 0 | 3 | 0 | 0 | 1 | 4 |
| February | 0 | 5 | 1 | 1 | 5 | 6 | 2 | 1 | 0 | 1 | 0 |
| March | 6 | 7 | 4 | 9 | 1 | 3 | 10 | 5 | 6 | 8 | 2 |
| April | 12 | 19 | 17 | 24 | 13 | 15 | 13 | 11 | 20 | 9 | 21 |
| May | 11 | 16 | 16 | 19 | 11 | 8 | 10 | 11 | 20 | 15 | 9 |
| June | 17 | 11 | 16 | 9 | 16 | 15 | 14 | 10 | 20 | 12 | 20 |
| July | 17 | 12 | 20 | 17 | 12 | 18 | 16 | 17 | 13 | 17 | 10 |
| August | 12 | 11 | 6 | 19 | 6 | 9 | 8 | 16 | 11 | 13 | 13 |
| September | 12 | 13 | 10 | 6 | 5 | 14 | 9 | 2 | 11 | 12 | 14 |
| October | 1 | 5 | 8 | 10 | 6 | 5 | 4 | 2 | 4 | 1 | 7 |
| November | 2 | 0 | 1 | 0 | 3 | 2 | 0 | 1 | 0 | 1 | 0 |
| December | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 1 | 0 | 0 |
The temperature in the region begins to increase from the end of February and reaches the highest point during June and July. January is the coldest month of the year. The air is highly humid throughout the year and winds are light in the district. But some of the cyclonic storm and depressions from the Bay of Bengal occur in the monsoon and post monsoon periods accompanied by heavy rain. Thunder storms occur during the period from March to May. Fog occurs in the winter months.
The total geographical area of the district is 1,85,058 hectare. The gross cropped area in the district is 1,34,518 ha and the net sown area is calculated as 73,619 ha. The area sown more than once is 59,351 ha. The cropping intensity is 182.72%. Out of the total cultivable area, 2.88 % is still cultivable waste. Out of the total geographical areas 1.70% areas covered as current fallow land. Permanent pastures and grazing land covered 3, 105 ha (1.68% of the total geographical area), Land under misc. trees groves not included in net area sown covered 4,760 ha (3.53 % of gross cropped area).
The status of soil ranges from old alluvial to new alluvial...The status of soil ranges from old alluvial to new alluvial. The soils are sandy to sandy loam in texture and clayey in low lying areas. Soils are mostly acidic and are characterized by medium to high organic carbon, low to medium phosphorus and potash content. The northern border is covered by Alluvium, accompanied by another thin belt of older alluvium; the rest of the District is covered by sandstone & shale.
| Sl. No. | Agro-ecological situation | Blocks covered | Characteristics |
|---|---|---|---|
| 01. | AES-1 | Sipajhar, Pub Mangaldai, Kalaigaon (Part), Khairabari (Part), Bechimari | Low land with lower elevation |
| 02. | AES-2 | Sipajhar, Pub Mangaldai, Dalgaon-Sialmari, Kalaigaon (Part), Bechimari, Pachim Mangaldai | Upland with medium rainfall |
| 03. | AES-3 | Sipajhar, Pub Mangaldai, Dalgaon-Sialmari | Medium land with medium rainfall |
| 04. | AES-4 | Kalaigaon (Part), Khairabari (Part) | Deep water with lower elevation |