Monsoon Calendar 2020  

#GS2 #Monsoons 

The Indian Meteorological Department has changed the dates of normal onset of monsoon across several parts of India, mainly for central and northwest India.  

What has changed?  

  • While the existing dates were based on rainfall records taken during 1901-1940, IMD now depends on data collected during 1961-2019 for forecasting the new monsoon onset dates and on data during 1971-2019 for the withdrawal dates.  
  • While monsoon onset date remains unchanged, on June 1 in Kerala, it has been delayed by three to seven days in Maharashtra, Gujarat, Madhya Pradesh, Chhattisgarh, Telangana, Andhra Pradesh, Odisha, Jharkhand, Bihar and parts of Uttar Pradesh.  
  • Over extreme northwest India, monsoon arrival data has been advanced to July 8 from July 15. There are, however, appreciable changes in the monsoon withdrawal dates.  
  • Monsoon will now withdraw from northwest India 14 days later. Yet, the final withdrawal date would remain unchanged, on October 15.  

Why?  

  • The major trigger for the revision of dates were the changes in the monsoon behaviour observed by IMD during the past many years, especially due to global warming.  
  • For instance, it has been observed for quite some time now that the movement of monsoon winds, after the initial onset over southern India, becomes sluggish over central India.  
  • IMD in 2018 formed a committee to assess such observations, check if they were statistically significant and suggest changes for the onset and withdrawal of monsoon dates over India. 
Print Friendly and PDF
blog comments powered by Disqus