Rajasthan: Climate and soils

Rajasthan, the largest state in India, has a climate shaped by the Aravalli range, which leaves the north-west dry and sandy and the south-east better watered. Rainfall comes from the South-West Monsoon and Western Disturbances, and the state is divided into 10 agro-climatic zones. The official sources used here describe climate, rainfall and agro-climatic zones; they do not give a classification of soils.

Seasons

• Rajasthan Tourism describes three main seasons: winter, monsoon and summer (it also speaks of four, adding post-monsoon).
• Summer: April to June; day temperatures rise up to 48°C. Areas around the Thar Desert are the harshest, while Mount Abu, Kumbhalgarh and Ranakpur stay pleasant.
• Monsoon: July to September; temperatures drop and rain transforms the arid landscape.
• Winter: sets in around October; temperatures range between 10°C – 30°C for most parts. In December and January they can drop to 0°C and below, with large day-night variation.

Rainfall and the Aravallis

• The South-West Monsoon and Western Disturbances are the main causes of rainfall.
• The Aravalli range runs from Guru Shikhar in the south-west to Khetri in the north-east and divides the state in a 60 by 40 ratio.
• About 60% of the state lies north-west of the range and 40% south-east of it.
• The range lies parallel to the incoming southwest monsoon winds and fails to intercept them, so the north-west is dry and sandy.
• The eastern and south-eastern parts are better watered and more fertile.
• Impervious rocks in the western parts can sometimes cause flooding.
• Farm output depends on the timely arrival of the monsoon and on the even spread of rain over the kharif season.

Agro-climatic Zones (Economic Review 2025-26)

• The 10 zones are based on climate, soil types, topography and cropping patterns.
• The north-western region (about 61 per cent of the state) is desert or semi-desert and rain-dependent; the south-eastern region (about 39 per cent) is fertile.

Zones and Major Crops

• I-A Arid Western Plain: Jodhpur, Phalodi, Barmer, Balotra; kharif bajra, moth & sesamum; rabi wheat, mustard & cumin seed.
• I-B Irrigated North Western Plain: Sriganganagar, Hanumangarh; kharif cotton & guar; rabi wheat, mustard & gram.
• I-C Hyper arid partially irrigated Western Plain: Bikaner, Jaisalmer and part of Churu; kharif bajra, moth & guar; rabi wheat, mustard & gram.
• II-A Transitional plain of Inland drainage: Sikar, Churu (rest), Jhunjhunu, Nagaur, Deedwana-Kuchaman; kharif bajra, guar & pulses; rabi mustard & gram.
• II-B Transitional Plain of Luni basin: Jalore, Pali, Sirohi (part), part of Beawar; kharif bajra, guar & sesamum; rabi wheat & mustard.
• III-A Semi-arid Eastern Plains: Jaipur, Ajmer, Dausa, Tonk, Khairthal-Tijara, Kotputli-Behror, Beawar (part); kharif bajra, guar & jowar; rabi wheat, mustard & gram.
• III-B Flood-prone Eastern Plain: Alwar, Deeg, Bharatpur, Dholpur, Karoli, Sawai Madhopur; kharif bajra, guar & groundnut; rabi wheat, barley, mustard & gram.
• IV-A Sub-humid Southern Plains: Udaipur, Chittorgarh (part), Rajasamand, Bhilwara, part of Sirohi; kharif maize, pulses and jowar; rabi wheat & gram.
• IV-B Humid Southern Plains: Banswara, Dungarpur, Pratapgarh, Salumber and Badi Sadri tehsil of Chittorgarh; kharif maize, paddy, jowar & blackgram; rabi wheat & gram.
• V Humid South Eastern Plain: Kota, Baran, Bundi, Jhalawar; kharif jowar & soyabean; rabi wheat & mustard.

Water Constraints

• Rajasthan has over 10.41 per cent of India's land area but barely 1.16 per cent of its water resources.
• It faces erratic rainfall, declining groundwater levels and expanding wastelands.
• Major projects to stabilise water supply include the Indira Gandhi Nahar Project, the Modified Parbati-Kalisindh-Chambal Link Project integrated with ERCP, and the Narmada Canal Project.