About:
- Long Period Average (LPA) is the averages of rainfall received over a 50-year period between 1951 and 2001. This average comes to 89 cm of rainfall.
- This is the average rainfall recorded during the months from June to September, calculated during the 50-year period, and is kept as a benchmark while forecasting the quantitative rainfall for the monsoon season every year.
Categories: IMD maintains five rainfall distribution categories on an all-India scale which are –
- Excess: If the rainfall is more than 110 % of this LPA.
- Above Normal: If the rainfall is between 104 and 110 % of this LPA.
- Normal: If the rainfall is between 96 and 104 % of this LPA.
- Below Normal: If the rainfall is between 90 and 96 % of this LPA.
- Deficient: If the rainfall is less than 90 % of this LPA.
