Climate of India

• Climate of India can be described as Tropical Monsoon Type.
• Places to the South of Tropic of Cancer remain hot with average temperature of 25 to 2 degrees Celsius, they do not experience winter at all.
• Places in the east-west coastline in India experience equable or maritime climate - not too hot or cold due to the influence of the sea.
• Places in the north of India have annual temperature up to 20 degrees Celsius and the coastal region has 2 to 5 degrees Celcius.
• Mawsynram - place with highest amount of rainfall in the world, 1182cm rainfall.
• Western Coast gets the most amount of rainfall in June due to South West Monsoon Winds, while the eastern coast remains dry through the summer and has rainfall in Winter.
• Places in the northern part of India experience extreme or continental climate, the places in the southern part experience moderate climate, and coastal region experiences equable climate.
• Temperature decreases with increasing altitude at 1 degree Celcius for every 166m.
• Places in the interior have extreme or continental climate, places near the sea have equable climate due to land breeze and sea breeze.
• The low pressure disturbances in winter are called the western depressions. These occur in north west India. These originate in the Mediterranean Sea.
• The upper currents or jet streams determine when the monsoon season will start and end.
• Four Seasons of India:

  • Hot Dry Season - March to May
  • Season of the South West Monsoon Winds or the Rainy Season - June to September
  • Season of the Retreating South West Monsoon Winds - October to November
  • Cold Season or the Season of the North East Monsoon Winds - December to February
• During hot dry season, the winds bring thunderstorms with strong dusty winds with a shower of rain mainly in Punjab, Haryana and Uttar Pradesh.
• Local winds:

  • Kali Baisakhi
  • Loo
  • Mango Showers
• Kali Baisakhi means the calamity of the month of Baisakhi, also called Norwesters as they usually blow in the north west direction. This is in the month of April and May and is good for the tea crop in Assam and rice in West Bengal.
• Loo is a hot dusty wind, also called sandstorm, which blows in the month of May and June in the Northern Plain and can bring temperature up to 45 to 50 degree Celcius.
• Mango showers occur in South India during April and May, and are good for mango, tea and coffee. They are premonsoon showers. They are Mango Showers in Kerala and Cherry Blossoms in Karnataka.
• Monsoon are periodic winds in which there is a complete reversal of wind direction every 6 months.
• The South East Trade winds are deflected to India as the South West Monsoon winds, picking up moisture from the Arabian Sea.
• South West Monsoon Winds are periodic winds, blowing from South West to North East, they are erratic, irregular and unpredictable and orographic in nature.
• South West Monsoon Winds divide into two branches -Arabian Sea branch and Bay of Bengal Branch
• Arabian Sea branch strikes the western coast of India on 1st June and gives orographic rainfall. The Deccan Plateau lying in the rain shadow of Western Ghats receive very little rainfall. The winds passing over Rajasthan do not saturate as the heat in the desert region increases the capacity to hold moisture.
• The total volume of the Arabian Sea Branch is more than that of the Bay of Bengal Branch because:

  • Arabian sea branch is much more bigger than the Bay of Bengal Branch
  • The whole of the Arabian Sea branch is used up by the whole country, but only part of it is used in South East India.
• Arabian Sea Brach is exhausted by the time it reaches Punjab.
• The Bay of Bengal Branch advances north eastward, and a part of it is intercepted by the North Eastern Hills - Garo, Khasi and Jaintia Hills. Mawsynram receives relief rainfall from this branch, but Shillong does not receive much, being in the rain shadow of the Khasi Hills.
• The remaining portion of the Bay of Bengal branch is deflected to the Himalayas, but the rainfall goes on decreasing.
• The withdrawal of the South West Monsoon winds is a much slower process and is the reversal of the process. The South West Monsoon winds travelled to the north, it reverses to the South. It blows from North East to South West, and causes rain the coastal region of India.
• The chief characteristics of the Cold Season in India are:

  • Clear skies
  • Pleasant weather
  • Low temperature
  • Slow northern winds
• Formulas:

  • Annual Temperature - Maximum temperature - Minimum temperature
  • Total Rainfall - Sum of rainfall of all months
  • Average annual rainfall - Sum of rainfall of all months divided by 12