Video summary
Rajasthan Computer Anudeshak Bharti 2026 | Rajasthan Geography Class – जलवायु Part 4 | Deendayal Sir
Main summary
Key takeaways
Main ideas / lessons: Climate of Rajasthan (Rainy season, winter, and key facts)
1) Rainy (Monsoon) Season in Rajasthan (mid-June to September)
- Rajasthan’s monsoon rainfall is mainly affected by:
- Arabian Sea monsoon
- Bay of Bengal monsoon
- (with additional variations/branches)
Arabian Sea monsoon
- Enters Rajasthan from the south-west direction.
- Produces limited rainfall because its path is parallel to the Aravalli range, so it doesn’t bring effective rainfall after entering.
- Result idea: rainfall is higher in southern Rajasthan, then reduces further north.
Bay of Bengal monsoon
- Reaches India by first affecting areas like Myanmar/Arakan (as described), then moves across the Indian subcontinent.
- After interacting with the Himalayan mountain region, it turns toward Rajasthan.
- Because it enters from the eastern side, it is called “Purvaiya (easterly) monsoon.”
- It brings the most rainfall to Rajasthan, but not fully enough because:
- by the time it reaches Rajasthan, moisture gets exhausted, resulting in less rainfall than expected.
Branch that may affect Rajasthan from the south
- Sometimes a branch of Bay of Bengal monsoon collides with the Chota Nagpur plateau (Jharkhand).
- It can then enter Rajasthan from the southern direction, linked to Jhalawar district (as stated).
2) Reasons Rajasthan gets less rainfall
The video lists four key reasons for low rainfall in Rajasthan:
- Arabian Sea monsoon runs parallel to Aravalli, reducing its effective impact.
- Greater distance from the Bay of Bengal → moisture decreases in monsoon winds, so rainfall becomes insufficient.
- Lack of natural vegetation reduces moisture retention and favorable conditions.
- Western desert region as Aravalli’s rain-shadow area → western Rajasthan receives little to no rainfall.
3) “Important facts” likely to be asked in exams (Monsoon origin/history + directional rainfall)
First discovery of monsoon
- Attributed to a Greek sailor named Hippolytus / Hippocrates (as said in subtitles).
Origin of the word “monsoon”
- Derived from an Arabic word: “Mosin.”
Early description of monsoon winds
- Mentioned by Arab geographer Al-Masudi:
- Summer: winds blow sea → land
- Winter: winds blow land → sea
Rainfall source in southern Rajasthan
- Areas around Dungarpur and Banswara receive rainfall from both Arabian Sea and Bay of Bengal monsoons.
- Jhalawar receives Bay of Bengal rainfall but (as stated) not Arabian Sea rainfall.
Rainfall gradient across Rajasthan
- Rainfall decreases from the south-east toward the north-west.
- Maximum rainfall: South-East
- Minimum rainfall: North-West
4) Numerical / definitional exam points (Rainfall, temperature, rainy days)
- Average temperature of Rajasthan (summer): 35–37°C
- Average temperature of Western desert region: 22°C
-
Average winter temperature of Rajasthan: 7–8°C (as later clarified)
-
Average annual rainfall (Rajasthan): 57.51 cm
- Average annual number of rainy days: 29 days
- “Rainy day” definition: day with ≥ 0.25 cm rainfall (as stated)
Thunderstorms
- Districts with maximum thunderstorms: Jaipur and Jhalawar
Common nickname facts
- “Cherrapunji of Rajasthan”: Jhalawar
- “Shimla of Rajasthan”: Mount Abu (Sirohi)
- “Barkhoyansh/B… of Rajasthan”:
- associated with Mount Abu, Sirohi (exact label unclear, but Mount Abu is emphasized)
5) Pre-monsoon rain and El Niño / La Niña effects
Pre-monsoon rain
- Called “Dogra.”
- Occurs before the monsoon begins (examples: April–May, up to roughly mid-June).
- Linked to Mediterranean cyclones / western disturbances moving into the region.
El Niño
- Warm Pacific Ocean current, activates around December.
- Effects:
- weakens monsoon
- causes late arrival and “slackness” (monsoon becomes less effective)
- Exam framing: weak monsoon → slackness in monsoon
La Niña
- Cold current
- If it gains strength:
- monsoon arrives earlier
- becomes stronger
- (Spelled “Lanino” in subtitles.)
6) Maximum and minimum rainfall (months, regions, districts, places)
Maximum rainfall
- Months with maximum rainfall: July and August
- Reason: both Arabian Sea and Bay of Bengal impacts strengthen during this period.
- Highest rainfall region: South-East
- Highest rainfall division: Kota division
- Highest rainfall district: Jhalawar
- ~100 cm for ~40 days (as stated)
- Second rainiest district: Banswara
- ~90 cm for ~38 days
- Place with maximum rainfall: Mount Abu (Sirohi district)
- ~150 cm for ~48 days (as stated)
Minimum rainfall
- Month with minimum rainfall: September
- Rain drops even within monsoon season due to reduced effectiveness/moisture.
- Division with minimum rainfall: Jodhpur
- Explanation given in the video links extremely high Mount Abu rainfall to Sirohi; remaining western context gets lowest.
- District with minimum rainfall: Jaisalmer
- ~10 cm for ~5 days
- Place with minimum rainfall: Sam (Jaisalmer)
- ~5 cm for ~3 days
- Driest place / minimum humidity emphasized repeatedly: Phalodi
7) Seasonal movement of the Sun (Equinox/Solstices) and winter start
- March 21: Sun shines on the Equator; moves northward afterward.
- June 21: Sun shines on Tropic of Cancer
- Longest/hottest day in the Northern Hemisphere.
- September 23: Sun shines again on the Equator
- After September: Sun moves south (Dakshinayan begins).
- December 22: Sun shines on Tropic of Capricorn
- Shortest and coldest day in the Northern Hemisphere.
- Southern Hemisphere is opposite (longest/hottest).
8) Winter split into two parts + returning monsoon
Winter season (as taught here)
- In Rajasthan: December to February
Winter is divided into
- Monsoon withdrawal / returning monsoon period: October–November
- Autumn (as named in subtitles): December–February
Returning (retreating) monsoon
- Explained as Arabian Sea monsoon returning after rainfall over other regions.
- Monsoon behavior linked to:
- cooling over Himalayas/upper regions
- increasing dryness in western areas, aiding later wind movement and moisture arrival
- Directional point:
- Retreating monsoon winds: north-east → south-west
Key exam question (as stated): Returning (retreating) monsoon is NOT responsible for rainfall in Rajasthan. Stated share of rainfall from returning monsoon: ~10%
“Pink winter”
- Mild cold after Diwali (around October/November) is called pink winter.
9) Rain due to Mediterranean cyclones / Western disturbances (Autumn-winter rain)
- Mediterranean cyclones (Western disturbances) bring rain in December/January.
- Mechanism described:
- In Dec–Feb, Sun is in the Southern Hemisphere
- Indian Ocean warms → air pressure decreases
- Winds shift direction and bring moisture into India via Iraq, Iran, Pakistan, Afghanistan, then into Rajasthan
Naming for exam purposes
- Called:
- Mediterranean cyclone rain / Western disturbance rain
- also described as “Golden Drop / Golden Shower”
Cropping connection
- Supports Rabi crops (wheat, gram, mustard, etc.)
- Considered beneficial for Rabi.
10) Transpiration, evaporation, humidity (month/district/place facts)
Transpiration
- Definition (as stated): “Vapor plus emissions”
- Maximum transpiration: June
- Maximum evaporation district: Jaisalmer
- Minimum transpiration month: December
Humidity
- Definition: Humidity = amount of moisture in the atmosphere
- Highest humidity month: August
- Most humid district: Jhalawar
- Wettest place: Mount Abu (Sirohi)
- Minimum humidity month: April
- District with minimum humidity: Jaisalmer
- Place with minimum humidity: Phalodi (stated as “Falauti” in subtitles)
Speakers / sources featured
- Deendayal Parik (main teacher/speaker; “Deendayal Sir”)
- Al-Masudi (historical source for monsoon wind description)
- Hippolytus / Hippocrates (Greek sailor mentioned for “first discovery of monsoon”)
- Arabic linguistic source (mentioned as the origin of the word “monsoon” → Mosin)
- Rajasthan exam bodies referenced:
- RPSC
- RSSB
- Subordinate Staff Selection Board