Rajasthan, situated at the northwestern part of India is the biggest state in the country of India and lies between 23°30′ and 30° 11′ North latitude and 69° 29′ and 78° 17′ East longitude. The state shares its north-western and western boundary with the Indo-Pakistan international border that extends about 1,070 km and touches the major districts Barmer, Bikaner, Sriganganagar and Jaisalmer. It is bounded on the west and northwest by Pakistan, on the north and northeast by Haryana &Uttar Pradesh, on the south-southeast and southwest by Madhya Pradesh and Gujarat States respectively. The huge portion of the state of Rajasthan is desiccated and houses the biggest Indian desert- the Thar desert known as the ‘Maru-kantar’. The oldest chain of fold mountains- the Aravali range splits the state into two geographical zones- desert at one side and forest belt on the other. Only 10% of the total geographical region lies under forest vegetation. The Mount abu is the only hill station of the state and houses the Guru Shikhar Peak that is the highest peak of the Aravali range with an elevation of 1,722 m. The area to the east of the hills is covered by the eastern plains and the Vindhyan plateau. Weather Seasons Rajasthan Geography
Weather Seasons of Rajasthan
The geographical diversity of the state causes varied weather conditions even during same season. However, Rajasthan has four distinct weather seasons: Weather Seasons Rajasthan Geography
1. The Hot weather season (March to Mid June)
2. The Season of general Rains or Rainy Season (June to September)
3. The Season of Retreating Monsoon (October – November)
4. The Cold Season (December to February)
The Hot Weather Season
The Hot whether season starts with movement of Sun toward the Tropic of Cancer in March. It ends in the month of June-July, when rainy seasons starts. In the months, the Sun overhead tropic of cancer so the temperature is Maximum in the month of June. The mean temperature of Rajasthan at this time is 38-39°C. However, the maximum temperature in western districts reaches at 45-50°C in day and minimum temperature 15-16°C.
- The difference in temperature in sandy region is generally found 32-35°C. The Aravalli Range has lower temperature (30°C) due to its high elevation.
Due to high temperature, the surface becomes very hot. Due to this, the hot and dry winds, known as ‘Loo’, blow from west to east direction.
Dry and hot winds known as ‘Loo’, blow in the afternoon, and very often, they continue to well into midnight. Dust storms in the evening are very common in May for south-eastern areas and in June for north-western part of state.
Average Mean Temperature: The maximum daily temperature in the western parts of Marusthali mainly at Bikaner, Phalodi, Barmer, and Jaisalmer goes upto 40-45 deg C.
Rainfall: Sometimes, the dust storms bring a welcome respite from the oppressing heat since they bring with them light rains and a pleasant cool breeze.
The Season of General Rains or Rainy Season
Due to high temperature in India in May – June, a center of low air pressure is created in the west and north-west India. While is temperature is low in Southern Hemisphere at this time, creates the high air pressure region.
The low air pressure created in the west and north-west India becomes so strong that it attracts the trade wind of Indian ocean coming from Southern hemisphere.
This southeast trade wind passes over the equatorial warm currents and brings the moisture in abundance. Then these winds enter the Bay of Bengal and Arabian Sea and caught in the air circulation over India.
These trade winds follow the south-west direction. So monsoon created by these winds is known as South-west monsoons.
However these branches tries to reach low air pressure area, west and north-west India, the Rajasthan gets very less rainfall because of the following reasons:-
- The Bay of Bengal branch already gives up its moisture during its passage through Ganga plain. Further, as Aravali range stretches from south-west to north-east direction, so western part of Rajasthan lies in leeward side of the Bay of Bengal branch and receives little or no rain from this branch.
- The same Aravalli Range lies parallel to the direction of Arabian Sea branch and fails to interrupt this branch of monsoon. However, in the southern Aravallis, the mountains have slight east-west span thus Mount Abu in south receives highest rainfall.
The Season of Retreating Monsoon
The Months of October and November are known for Retreating Monsoons and it withdraws from Rajasthan, Gujarat, Western Ganga plain and the Central Highlands by the end of the month.
By the end of September, the southwest monsoon becomes weak as the low Pressure trough of the Ganga plain starts Moving Southward in response to the Southward Movement of the Sun.
After 22nd September, the Sun begins to overhead in Southern Hemisphere. Due to this high air pressure area is created in southern hemisphere and low air pressure area in north and north-west India and due to this air Pressure difference, the monsoon retreat from western Rajasthan by the month of October. Weather Seasons Rajasthan Geography
The retreating south-west monsoon season is marked by clear sky and rise in temperature. The land is still moist. Due to this high temperature and humidity, the weather becomes oppressive. This Process is commonly known as ‘October heat’.
Average Mean Temperature: The temperature maximum ranging from 33-37 deg C and minimum ranging from 18 – 22 deg C.
The Cold Weather Season
This Season starts from December and continuous till February.
Average Mean Temperature: Ranges from 12 deg. C in North of State to 16 deg. C in the south in January.
Due to high air pressure in west and north-west India and low air pressure in Indian Ocean, the air flow from west and north-west India to Indian Ocean.
During this time, the north-western parts of India get the rainfall from shallow cyclonic depressions originating over the East Mediterranean Sea. This rainfall is also called ‘Mavath’.
During the cold season, the sun migrates to the southern hemisphere and creates high-pressure condition over the northern plain. As a result, winds start blowing from northwestern high pressure zone to the low air pressure zone over the Indian Ocean in the South.
shallow cyclonic depressions at certain time interval originating over the East Mediterranean Sea and travelling eastwards across West Asia, Iran, Afghanistan and Pakistan before they reach the northwestern parts of India. On their way, the moisture content gets augmented from the Caspian Sea in the north and the Persian Gulf in the south. Weather Seasons Rajasthan Geography