1
CLIMATE
OF
INDIA
2
CLIMATIC EXTREMES - TEMPERATURE
o
•55
C
• Rajasthan on a hot summer day
o
•-50 C
• Ladakh on a winter dawn
3
CLIMATIC EXTREMES RAINFALL
•>2500 cm
• Mawsynram (Meghalaya)
•<13 cm
• Thar desert
4
CLIMATIC EXTREMES –
ANNUAL RANGE OF
TEMPERATUTE
o
•3
C
• Malabar Coast
o
•20 C
• Interior India (Delhi)
5
SO, WHAT’S COMMON ?
• The entire sub-continent receives rainfall due to
Monsoon winds
6
FACTORS AFFECTING
CLIMATE OF INDIA
1.
Latitude
2.
Physical features
3.
Altitude
4.
Distance from the Sea
5.
Other minor factors
7
INFLUENCE OF LATITUDE
• Tropic of Cancer passes through India
• Northern half – Temperate
• Southern Half – Torrid
• Yet the sub-continent is said to have a
sub-tropical climate!!!
• No striking difference of temperature
• Seasonal rainfall due to monsoons
8
INFLUENCE OF RELIEF HIMALAYAS
• Himalayas
• Stop cold winds from north
• Help to create HT-LP regime
• Pull monsoons
• Force monsoons to shed moisture in
India
• Arakan Yoma Range
• Deflect the monsoons into India
9
INFLUENCE OF RELIEF – OTHER FEATURES
• Western Ghats
• Uneven rainfall in the peninsula
• Aravallis
• Dry climate in Rajasthan
10
INFLUENCE OF ALTITUDE
• Deccan Plateau cooler than Northern Plains in summer
• Snowfall in Himalayas
11
DISTANCE FROM THE SEA
• Equable climate in coastal areas
• Extreme climate in the interior
12
OTHER FACTORS
• Western disturbances
• Winter Rainfall in Punjab
• Conditions surrounding the sub-continent
• Indian Ocean
• Africa
• Jet Streams
• Not much known
Seasons in India
13
14
15
March to May
 Sun directly overhead on equator on
March 21
 Sun directly overhead on Tropic of Cancer
on June 21

16
From March to May (Movement of sun
from Equator to Tropic of Cancer)
 High temperature, low pressure over the
northern plains
 Low temperature, slightly high pressure
over the Peninsular Plateau
 High pressure over Indian Ocean

17
Monsoon winds not drawn into India due
to HP over Peninsula
 Hot ‘Loo’ in northern plains
 Kalbaisakhi in West Bengal
 Mango Showers in Kerala

LOO
THE INDIAN
SUMMER
March to May
LP
KALBAISAKHI
HP
MANGO SHOWER
HP
HP
19
THE INDIAN MONSOON
20
MONSOON – MEANING
• Refers to a seasonal wind which blows over the Indian
sub-continent
• Sea to land in summer
• Land to sea in winter
21
MONSOON – UNIQUE
FEATURES
• Brings rains to the sub-continent
• Varies in strength
• Uncertain and Uneven
22
MONSOON - TIMELINE
• June to September
• Sun moves from Tropic of Cancer to
Equator
• Causes LP in peninsular India
• By August, monsoon spreads all over India
23
MONSOON – ARRIVAL
TIMES
• Monsoon arrival dates
• Western Ghats, NE states – 15th June
• North-western India, Eastern Ghats – 1st July
• Northern Plains, Central India – 15th July
• Kanyakumari is the first place to receive
rainfall
• Kerala is the first state to receive rainfall
THE INDIAN
MONSOON
JUNE TO SEP
LP
LP
HP
HP
25
MECHANISM OF MONSOONS
26
DISTRIBUTION OF
RAINFALL
• Areas of Heavy Rainfall (>200 cm)
• Windward Side of Western Ghats
• Eastern Himalayas
• West Bengal
• Areas of Moderately heavy rainfall (100-200 cm)
• Deccan Plateau
• Middle Ganga Valley
• Orissa
27
DISTRIBUTION OF
RAINFALL
• Areas of Moderate Rainfall (50-100 cm)
• Eastern Ghats
• Upper Ganga VAlley
• Gujarat, Punjab, Rajasthan
• Areas of Scanty Rainfall (<50 cm)
• Western Rajasthan
• Northern J & K
• Kutch
28
Rainfall
Distribution
Map of India
29
FEATURES OF INDIAN
RAINFALL
• Occurs from June to September
• Distinct Rainy Season
• Erratic and unpredictable
• Unevenly distributed
• Orographic rainfall
• Cyclones and convectional rainfall
30
THE RETREATING MONSOON
Retreating Monsoon - Meaning
31
► Strength
of monsoon decreases
► Extent to which monsoons were able to
reach from June to September decreases
► Direction remains the same
► Also called ‘Retreating SW Monsoon’
Retreating Monsoon - Causes
► Sun
32
moves from Equator towards Tropic of
Capricorn
► Temperatures drop
► LP replaced by HP
Retreating Monsoon - Dateline
33
► October
and November
► Monsoon withdrawal dates




Northern Plains – 15th September
Western Ghats – 1st October
Kolkata – 15th October
Kerala – 15th November
Retreating Monsoon - Summary
34
► Monsoons
decrease in intensity
► LP gradually replaced by HP
► In the northern plains, it is oppressively
hot – a condition called ‘October Heat’
► Cyclones hit east coast and Bangladesh
► Kerala last state from where monsoons
withdraw
THE RETREATING
MONSOON
OCT AND NOV
LP
LP
HP
HP
36
WINTERS OF INDIA
37
The Indian Winter - Dateline


November to February
Sun descends towards Tropic of Capricorn
THE INDIAN
WINTER
WESTERN
DISTURBANCES
DEC TO FEB
HP
HP
NORTH EAST
MONSOON
LP
LP
39
WINDS IN WINTER
• Although India lies in Trade Wind Belt,
• Himalayas & Arakan Yoma Ranges do not
allow them to come to India
40
WINDS IN WINTER
•
•
•
•
•
•
•
HP over Land, LP over Sea
Winds move from Land to Sea
Deflected due to Coriolis Effect
Blow from NE to SW
Called NE monsoon winds
Direction coincides with Trade Winds
SW Monsoon winds ‘reverse’ in direction
41
Summary of Indian Winter





Cool and Pleasant
December to February
Sun shines in the Southern Hemisphere
HP over land; LP over Sea
Winds move from Land to Sea (North East
Monsoons) – a phenomenon called ‘Reversal
of Winds’
42
Summary of Indian Winter




Western Disturbances come to India
Cause cyclonic rainfall in Punjab
Move along the foothills of the Himalayas into
the Bay of Bengal
NE Monsoons joined by Western Disturbances
cause rainfall in Tamil Nadu (Palni, Javadi and
Shevaroy hills)