Monsoon of South Asia
![Annual average monsoon precipitation in India over 110 years. The long-term average has been 899 millimeters of precipitation.[1] However, the monsoon varies over the Indian subcontinent within a ±20% range. Rains that exceed 10% typically lead to major floods, while a 10% shortfall is a significant drought.[2]](/uploads/202501/20/Monsoon_annual_trends_for_India_over_110_years,_average_precipitation_over_the_nation4633.png)
The monsoon of South Asia is among several geographically distributed global monsoons. It affects the Indian subcontinent, where it is one of the oldest and most anticipated weather phenomena and an economically important pattern every year from June through September. Yet it is only partly understood and notoriously difficult to predict. Several theories have been proposed to explain the origin, process, strength, variability, distribution, and general vagaries of the monsoon, but understanding and predictability are still evolving.