Rainfall Forecast (Geography)
Rainfall Forecast (Geography)
Why In News:
The India Meteorological Department has forecast below normal rainfall for August 2026 and for the August-September period combined, even as the monsoon staged a partial recovery in July after a weak June.
Source: The Hindu, Page 10, 1 Aug 2026, 'India likely to receive below-normal rainfall this month, says IMD'.
The Forecast
Quantum: Rainfall for August and the combined August-September period is expected at about 94 percent of the Long Period Average (LPA).
July Recovery: All India rainfall in July was about 1 percent above normal, even though the cumulative June-July rainfall remained around 13 percent below normal.
Temperature Outlook: Above normal maximum temperatures are likely to persist across most of the country through August.
Regional Variation
Central India: Swung from a roughly 50 percent deficit in June to a 33 percent surplus in July, ending the season so far with a 4 percent excess.
District Level Deficiency: Close to 42 percent of the districts assessed recorded deficient rainfall during June and July.
Indian Ocean Dipole: Neutral IOD conditions currently prevail, but a positive IOD is expected to develop by September, which typically supports the Indian monsoon.
Key Facts for Prelims
Long Period Average (LPA): LPA refers to the average rainfall calculated over a long reference period (currently 1971–2020) and serves as the benchmark for assessing monsoon performance in India.
It helps the India Meteorological Department compare actual rainfall with historical trends to determine whether a monsoon season is normal, deficient, or excess.
Rainfall Classification (based on % of LPA):
Deficient:< 90% of LPA (indicates drought-like conditions, stress on agriculture and water resources)
Below Normal:90% – 96% of LPA (mild shortfall, may affect crop yields)
Normal:96% – 104% of LPA (considered ideal for agriculture and economy)
Above Normal:104% – 110% of LPA (higher rainfall, beneficial but may cause localized flooding)
Excess:> 110% of LPA (very high rainfall, increased risk of floods and infrastructure damage)
Share in Annual Rainfall: The southwest monsoon contributes about 70 to 75 percent of India's total annual rainfall.
Nodal Body: IMD functions under the Ministry of Earth Sciences.