India records its hottest August since 1901; IMD forecasts below-normal September rain
A record-hot August, a 14% rain deficit and a strong El Niño: how bad can September get?
Published 1 September 2026. Written by Pratidin from the reports linked at the end; every fact checked by a separate review before publishing. How we work
The India Meteorological Department (IMD) said on 31 August 2026 that August 2026 was India's warmest August since national records began in 1901. The all-India mean temperature was 28.01°C against a normal of 27.34°C, and the average minimum temperature of 24.36°C (normal 23.68°C) was also the highest for the month. Rainfall in August was 213.3 mm, 16.3% below normal and the seventh-lowest August total since 2001. The cumulative deficit of the south-west monsoon from 1 June to the end of August stood at about 14%.
For September, the last month of the June to September monsoon season, IMD forecast below-normal rainfall for the country as a whole: less than 91% of the Long Period Average (LPA) of 167.9 mm, the 1971-2020 average for the month. Parts of northwest, northeast, east and east-central India and southeast peninsular India may still get normal or above-normal rain. Monthly maximum temperatures are likely to be above normal over most of the country, and minimum temperatures above normal except in parts of northwest, west-central and northeast India.
IMD Director General Mrutyunjay Mohapatra linked the weak rain to El Niño: strong El Niño conditions prevail over the equatorial Pacific and are expected to strengthen further. The Indian Ocean Dipole (IOD), which can offset El Niño's effect when positive, is neutral; IMD's model expects it to stay neutral through September, while some international centres see a possible shift to a positive phase. IMD warned that below-normal rainfall can hurt agriculture, water resources, hydropower and drinking water availability and increase heat stress, and advised water conservation and contingency planning for agriculture.
Prelims facts
- August 2026 was India's warmest August since 1901, with a mean temperature of 28.01°C against a normal of 27.34°C.
- August rainfall was 213.3 mm, 16.3% below normal; the season deficit to end-August was about 14%.
- IMD forecasts September 2026 rainfall below 91% of the LPA of 167.9 mm (1971-2020 base).
- Strong El Niño conditions prevail and are expected to strengthen; the Indian Ocean Dipole is neutral.
- Maximum and minimum temperatures in September are likely to be above normal over most parts of India.
Quick recall
- All-India mean temperature in August 2026?
- 28.01°C, against a normal of 27.34°C; warmest August since 1901
- August 2026 rainfall and departure?
- 213.3 mm, 16.3% below normal
- Monsoon deficit from 1 June to end-August 2026?
- About 14%
- September LPA and base period?
- 167.9 mm, based on 1971 to 2020
- IMD's September 2026 rainfall forecast?
- Below normal: under 91% of the LPA
- State of ENSO in August 2026?
- Strong El Niño, expected to strengthen
- State of the Indian Ocean Dipole in August 2026?
- Neutral
- Positive IOD means?
- Western Indian Ocean warmer than the eastern Indian Ocean; tends to favour Indian rainfall
Prelims practice question
With reference to IMD's outlook for September 2026, consider the following statements:
1. All-India rainfall is forecast to be below 91% of the Long Period Average.
2. The Long Period Average used is the mean rainfall over 1951 to 2000.
3. The Indian Ocean Dipole was in a strong positive phase at the time of the forecast.
Which of the statements given above is/are correct?
- 1 only
- 1 and 2 only
- 2 and 3 only
- 1, 2 and 3
Show answer
Answer: (a) 1 only. Statement 1 is correct: IMD forecast below-normal rain, under 91% of the LPA of 167.9 mm. Statement 2 is incorrect: the LPA is based on 1971 to 2020. Statement 3 is incorrect: the IOD was neutral; only some international models suggested a possible positive phase from September.
Use this in UPSC Mains: previous-year questions
Recurring theme: Monsoon variability, El Niño and the Indian Ocean Dipole, and drought preparedness
- How to use this
Use the 2026 El Niño season to illustrate the drought risk the question describes and the preparedness measures that follow from IMD forecasts.
- IMD says strong El Niño conditions prevail and are expected to strengthen, while the Indian Ocean Dipole, which can offset El Niño when positive, is neutral.
- August 2026 rainfall was 16.3% below normal, the season deficit to end-August was about 14%, and September is forecast below 91% of the LPA of 167.9 mm.
- Preparedness: district crop advisories and contingency crop plans from IMD forecasts, priority to drinking water in reservoir releases, timely drought declaration under the Manual for Drought Management, and fodder banks.
- How to use this
Use August 2026 to illustrate the monsoon's variability and its dependence on ocean-atmosphere signals, which shape food and water security.
- August 2026 was India's warmest since 1901 (mean 28.01°C against 27.34°C) and its rainfall of 213.3 mm was 16.3% below normal.
- IMD linked weak rain to strong El Niño in the equatorial Pacific; a positive Indian Ocean Dipole can offset it, but it is neutral now.
- IMD warned below-normal rain can hurt agriculture, water resources, hydropower and drinking water, and advised water conservation and contingency planning for agriculture.
IMD's outlook turns on exactly this pairing: a strong El Niño with a neutral IOD that is not offsetting it.
Mains practice question
India recorded its warmest August since 1901 and IMD expects a below-normal September amid a strong El Niño. Discuss the likely impacts and the preparedness measures needed. (250 words)
Model answer
India's August 2026 was the warmest since 1901 (mean 28.01°C against a normal of 27.34°C), rainfall was 16.3% below normal, and IMD forecasts September rain below 91% of the Long Period Average as a strong El Niño persists.
Impacts
- Agriculture: stress on kharif crops at grain filling and poorer soil moisture for rabi sowing, since much farmland is rain-fed.
- Prices and growth: analysts already list El Niño as a risk to food inflation and growth after the Q1 2026-27 GDP data.
- Water and energy: lower reservoir inflows affect drinking water, irrigation and hydropower.
- Health: record warm nights (minimum 24.36°C) raise heat stress, especially for outdoor workers.
Preparedness measures
- Early warning: use IMD's extended-range forecasts to issue district crop advisories and contingency crop plans.
- Water management: prioritise drinking water in reservoir releases; promote micro-irrigation and recharge.
- Drought management: apply the Manual for Drought Management for timely declaration and relief; keep rural employment works and fodder banks ready.
- Heat action plans: extend city and district heat plans, work-hour changes and cooling shelters.
- Price management: use buffer stocks and open market sales to check food inflation.
Long-term steps
- Crop diversification towards millets and pulses in rain-fed areas.
- Better seasonal forecasting that combines ENSO and Indian Ocean Dipole signals.
- Crop insurance with faster claims.
A hot, dry August is a reminder that monsoon risk management must shift from relief after drought to planning before it.
The basics
Why this matters
Much of India's farmland depends on rain, and the June to September south-west monsoon brings most of the year's rainfall. When the monsoon falters, crops, reservoirs, hydropower and drinking water all suffer. On 31 August 2026 the India Meteorological Department (IMD) reported the warmest August in its records and warned that September, the last monsoon month, will also be dry. Three ideas explain this: how IMD measures 'normal', how El Niño affects the monsoon, and what the Indian Ocean Dipole does.
Measuring normal
IMD compares rainfall with a Long Period Average (LPA), the mean over 1971 to 2020. For September the LPA is 167.9 mm. A forecast of 'below normal' for September means less than 91% of that figure.
Why the monsoon weakened
The monsoon is driven by the contrast between a hot land mass and cooler seas, and by the large circulation of air over the tropical Pacific and Indian Oceans. During El Niño (see El Niño and the monsoon), the central and eastern equatorial Pacific warms. Rising air shifts eastward, and the sinking branch of the circulation tends to settle over the Indian region, suppressing rain.
- 1Pacific warmsSea surface in the central and eastern equatorial Pacific becomes warmer than normal
- 2Circulation shiftsThe zone of rising air and heavy rain moves east, away from the western Pacific
- 3Air sinks over IndiaDescending air over the Indian region discourages cloud formation
- 4Rain falls shortMonsoon rainfall is more likely to be below normal, and temperatures rise
El Niño is not destiny. The Indian Ocean Dipole, a see-saw of sea temperatures across the Indian Ocean, can soften or deepen El Niño's effect. A positive dipole, with a warmer western Indian Ocean, tends to help Indian rainfall. In 2026 the dipole is neutral, and IMD expects it to stay neutral through September, though some international centres see a shift to positive from September.
The forecast in one view
- All-India rainfall under 91% of the LPA of 167.9 mm
- Maximum temperatures above normal over most parts
- Minimum temperatures above normal over most parts
- Normal or above-normal rain in parts of northwest, northeast, east and east-central India
- Normal or above-normal rain in some areas of southeast peninsular India
- Normal or below-normal minimum temperatures in parts of northwest, west-central and northeast India
Go deeper
In one line: August 2026 was India's warmest August since 1901, rainfall was 16.3% below normal, and IMD expects September rain to be below 91% of the Long Period Average as a strong El Niño persists.
Why it matters for UPSC
Monsoon mechanisms (El Niño, the Indian Ocean Dipole, the LPA) are regular Prelims material, and Mains asks about monsoon variability, drought preparedness and climate change. The data also links to GS3 topics: farm output, food inflation and water security.
The core idea
IMD judges a season against the Long Period Average. This year the Pacific is in a strong El Niño phase, which usually weakens Indian rainfall; see El Niño and the monsoon. The Indian Ocean Dipole is neutral, so it is not offsetting El Niño. The result is a dry, hot end to the season.
Numbers and dates to remember
- Release: 31 August 2026; IMD Director General Mrutyunjay Mohapatra
- August 2026 mean temperature: 28.01°C (normal 27.34°C), highest since 1901
- August 2026 minimum temperature: 24.36°C (normal 23.68°C)
- August rainfall: 213.3 mm, 16.3% below normal, seventh-lowest August since 2001
- Season deficit from 1 June to end-August: about 14%
- September LPA: 167.9 mm (1971-2020); forecast below 91% of LPA
Where to go next
- Long Period Average: how IMD defines normal rainfall
- El Niño and the monsoon: why a warm Pacific dries India
- Indian Ocean Dipole: the Indian Ocean's own see-saw
Go deeper: a hot, dry end to the monsoon
What IMD said. Strong El Niño conditions prevail over the equatorial Pacific and are expected to strengthen. The Indian Ocean Dipole is neutral. IMD warned that below-normal rain can hurt agriculture, water resources, hydropower and drinking water supply and raise heat stress, and advised water conservation, careful resource management and contingency crop planning.
Why the heat and the dry spell go together. Less cloud and rain means more sunshine reaching the ground and less cooling from evaporation, so a weak monsoon month is often a hot one. The record minimum temperature (24.36°C) shows that nights stayed warm too, which matters for human health and for crops.
The farm and price angle. A dry September hurts kharif crops during grain filling and cuts soil moisture for rabi sowing. The same week, analysts named El Niño as a risk to growth and food inflation after the April to June GDP data. Past El Niño years such as 2009 and 2015 saw deficient monsoons, but not every El Niño year does; the dipole and other factors matter.
The climate angle. A single hot month is weather, not proof of a trend. But a record set against a series going back to 1901 fits the warming seen across recent years. It supports the case for heat action plans, crop diversification and water storage, rather than relying on the Long Period Average to hold.
Reading forecasts carefully. A forecast of 'below 91% of LPA' is an all-India average. It hides regional variation: IMD expects parts of the northwest, northeast, east and east-central India to get normal or above-normal rain even in a dry month. See El Niño and the monsoon for why.
Long Period Average
How IMD defines normal rainfall
In one line: The Long Period Average (LPA) is the average rainfall over a long base period, now 1971 to 2020, against which IMD compares actual and forecast rainfall.
The idea from zero
Rainfall varies a lot from year to year, so 'normal' has to mean an average over many years. IMD uses a 50-year base. For the whole June to September season the LPA is about 87 cm. For September alone it is 167.9 mm. Forecasts are stated as a percentage of the LPA.
How it is used
For a monthly forecast such as September's, IMD calls rainfall below normal if it is under 91% of the LPA, normal if it is between 91% and 109%, and above normal if it is over 109%. The September 2026 forecast is 'below normal', under 91%.
Where to go next
El Niño and the monsoon
Why a warm Pacific tends to dry India
In one line: El Niño is the warm phase of a Pacific Ocean cycle, the El Niño Southern Oscillation (ENSO), in which the central and eastern equatorial Pacific becomes warmer than normal; it often weakens the Indian monsoon.
The idea from zero
Normally, trade winds push warm water towards the western Pacific, where air rises and rain falls, while air sinks over the eastern Pacific. In El Niño the trade winds weaken and warm water spreads east. The rising branch of the circulation shifts east and sinking air tends to settle over the Indian region, reducing rain. The cool phase is called La Niña and usually favours the monsoon.
Why it is in the news
IMD says strong El Niño conditions prevail and will strengthen. August 2026 rainfall was 16.3% below normal and September is forecast below normal. El Niño raises the risk of a weak monsoon but does not guarantee one.
Where to go next
Indian Ocean Dipole
The Indian Ocean's own see-saw
In one line: The Indian Ocean Dipole (IOD) is the difference in sea surface temperature between the western Indian Ocean and the eastern Indian Ocean near Indonesia.
The idea from zero
In a positive IOD, the western Indian Ocean is warmer than the east. This tends to favour rainfall over India and can offset part of El Niño's drying effect. In a negative IOD the east is warmer, which tends to be less favourable. When the difference is small, the IOD is called neutral.
Why it is in the news
In August 2026 the IOD was neutral. IMD's model expects it to stay neutral through September, while some international centres indicate a possible shift to a positive phase from September. A neutral IOD gives no cushion against the strong El Niño.
Where to go next
Take the 1 September 2026 quiz: 30 Prelims-style questions with answers