India is entering the final month of the 2026 southwest monsoon with a significant rainfall deficit. The IMD has forecast below-normal rainfall for September after August ended with more than a 16% shortfall, raising concerns for water resources, agriculture and temperatures.
September Rainfall Forecast: What IMD Says
The India Meteorological Department has forecast below-normal rainfall across India in September, the final month of the southwest monsoon season. The latest outlook, released on August 31, comes after the country recorded a rainfall deficit of more than 16% during August.
The IMD said rainfall for September is expected to be below 91% of the long-period average. With the June to August rainfall already at only about 84% of normal, the monsoon season is now likely to finish with an overall deficit.
The forecast does not mean every part of the country will remain completely dry. Some regions are expected to receive normal or above-normal rainfall, while others could see significantly lower rainfall than usual.
For September, the IMD has identified parts of Odisha, eastern Madhya Pradesh, Bihar, Jharkhand, eastern Uttar Pradesh, Nagaland, Manipur, Mizoram and Ladakh as areas where rainfall could be around normal. Much of the remaining country is expected to see below-average rainfall.
August Rainfall Deficit Raises Monsoon Concerns
August is normally one of India’s important monsoon months, accounting for roughly 29% of the seasonal rainfall, compared with around 32% in July. A weak August therefore has a significant impact on the overall monsoon balance.
According to the IMD, India received more than 16% less rainfall than normal in August. By the end of the month, 312 of the 741 districts being monitored had recorded deficient rainfall, while another 38 districts had large rainfall deficiency.
The regional picture was uneven. Southern peninsular India recorded a rainfall deficit of more than 27% in August, while central India and the eastern and northeastern regions each recorded deficiencies of around 16%. Northwest India was about 10% below normal.
This means the national rainfall deficit does not tell the entire story. Some districts have received adequate rainfall, while others have faced repeated dry spells.
El Niño Adds Pressure on the Indian Monsoon
The IMD has linked the weakening monsoon activity partly to the strong El Niño conditions prevailing over the equatorial Pacific. The weather phenomenon can influence atmospheric circulation patterns and reduce rainfall over parts of India.
The IMD said four low-pressure systems developed during August and collectively persisted for 26 days. However, much of their rainfall activity remained concentrated over the Indo-Gangetic Plains rather than being distributed evenly across the country.
This explains why some areas experienced intense rain and flooding while other regions were simultaneously reporting rainfall shortages.
The weather pattern also shows why a national rainfall average needs to be interpreted carefully. A few episodes of heavy rain can produce flooding in one region without correcting rainfall deficits in another.
Delhi-NCR Could See Rain Before Dry Conditions Return
Delhi and parts of north India are expected to see another spell of widespread rain in the opening days of September.
The IMD forecast indicates heavy rainfall activity across several northern and central regions through the first part of the month. Delhi, Punjab, Haryana, Uttar Pradesh, Uttarakhand, Himachal Pradesh and Jammu and Kashmir are among the areas being watched for rainfall activity.
The current spell does not necessarily contradict the broader September forecast. A month can record several intense rain events while still finishing below its normal rainfall total.
For Delhi-NCR residents, this could mean a familiar pattern of short periods of heavy rain followed by warmer and comparatively drier conditions.
That distinction is important for commuters and city authorities. A below-normal monthly forecast does not eliminate the possibility of sudden heavy showers, waterlogging or localised flooding.
Mumbai Faces a Drier September Outlook
Mumbai is another major city where the contrast between intense monsoon expectations and actual rainfall has become noticeable.
The city ended August with a significant rainfall shortfall. According to The Indian Express, Mumbai received only about 35% of its monthly average rainfall in August, making it one of the city’s driest August periods in recent years.
For September, the IMD has forecast below-normal rainfall for Mumbai, along with a rise in maximum temperatures. Some drizzle is expected in the immediate period, but the outlook does not indicate a return to consistently heavy monsoon rainfall.
For Mumbai, lower rainfall could reduce the frequency of waterlogging caused by prolonged rain, but it also creates concerns about water availability if the dry pattern continues.
Maharashtra Could Remain Warmer and Drier
The September outlook is also significant for Maharashtra because large parts of the state are expected to receive below-normal rainfall.
The Times of India reported that the IMD’s September rainfall probability map placed sizeable portions of Maharashtra in the below-normal category. Eastern parts of the state may receive normal or above-normal rainfall in some pockets.
The temperature outlook is also notable. Most of Maharashtra has been placed in the above-normal category for September, suggesting that the state could experience a combination of reduced rainfall and higher temperatures.
Nagpur and Vidarbha are particularly relevant because August was exceptionally dry. Vidarbha recorded a 58% rainfall deficit during August, while Nagpur district received about 71% less rainfall than normal for the month, according to local IMD data reported by The Times of India.
Such conditions can affect soil moisture, groundwater recharge and irrigation requirements.
What Below-Normal Rain Means for Farmers
The biggest impact of a weak September monsoon could be felt in agriculture.
By the beginning of September, much of the kharif sowing activity has already taken place. The concern now shifts from sowing to maintaining standing crops.
Adequate rainfall during this stage can support crop growth and reduce the need for irrigation. If rainfall remains weak, farmers may have to depend more heavily on groundwater, canals or other irrigation sources.
The Times of India reported that the IMD outlook could affect kharif crop prospects, with farmers potentially facing higher irrigation and input costs if dry conditions continue.
However, the impact will vary considerably by crop, soil conditions, irrigation availability and the rainfall received during earlier months.
A deficient September therefore does not automatically mean widespread crop failure. It means the risk of water stress becomes more important in already dry regions.
Why Cities Could Also Feel the Impact
The effects of a weak monsoon are not limited to rural areas.
Urban water supply systems depend partly on reservoir levels and groundwater recharge. Lower rainfall can reduce natural replenishment, particularly in cities and regions that have already experienced deficient rainfall during earlier months.
At the same time, a weaker monsoon can create higher temperatures and increase demand for electricity because of greater use of air conditioners and cooling systems.
There is another complication. Below-normal rainfall for the month does not mean there will be no extreme weather.
The IMD has forecast heavy to very heavy rainfall in several parts of central, eastern and northeastern India during the first week of September, including isolated extremely heavy rainfall over Chhattisgarh on September 1.
Cities therefore need to prepare for both possibilities: longer dry spells and sudden intense rain.
August Was Also India’s Warmest on Record
The rainfall deficit was accompanied by an unusual temperature pattern.
The IMD said August 2026 was the warmest August in India since records began in 1901, with the country’s mean temperature reaching about 28.01°C, around 0.67°C above the long-period average.
South peninsular India recorded its second-warmest August, while east and northeast India experienced their third-warmest August. Northwest India recorded its fifth-warmest August in the 126-year record.
The combination of below-normal rainfall and above-normal temperatures is important because dry conditions can become more stressful when temperatures remain elevated.
For residents of major cities, this could translate into warmer afternoons, higher cooling demand and more noticeable swings between hot periods and short bursts of rain.
What September’s Forecast Means Overall
The September forecast is a warning about the direction of the monsoon rather than a prediction that every part of India will remain dry.
Some regions are expected to receive normal or above-normal rainfall, and short-duration heavy rain events are still possible. At the same time, the national rainfall balance is already weak, and the IMD expects September to remain below normal.
For cities such as Mumbai, Delhi, Pune and Nagpur, the implications will differ depending on local rainfall, reservoirs and weather systems. For farmers, the key issue will be soil moisture and irrigation availability.
The most important point is that India’s monsoon season is not judged only by individual rainy days. The cumulative rainfall across regions and over the entire June to September period determines the broader water and agricultural picture.
With September now underway, the next few weeks will determine how much the country can recover from the deficit accumulated during August and the earlier part of the season.
Key Takeaways
- The IMD has forecast below-normal rainfall across India for September, the final month of the 2026 southwest monsoon.
- India recorded more than a 16% rainfall deficit in August, while 42% of monitored districts had deficient rainfall by August 31.
- Mumbai, large parts of Maharashtra and several other regions face a drier September outlook, although local heavy rain spells remain possible.
- August 2026 was India’s warmest August since 1901, adding to concerns about water stress and higher temperatures.
Frequently Asked Questions
What is the IMD’s September 2026 rainfall forecast?
The IMD expects India’s overall rainfall in September to remain below normal. It has forecast rainfall below 91% of the long-period average for the month.
Why was August rainfall deficient in India?
The IMD has attributed the weak rainfall partly to strong El Niño conditions. Although several low-pressure systems developed during August, their rainfall was concentrated mainly over the Indo-Gangetic Plains rather than being evenly distributed across the country.
Will cities like Mumbai and Delhi receive no rain in September?
No. A below-normal monthly forecast does not mean a city will remain dry. Short spells of heavy or moderate rain can still occur. Mumbai is expected to see some drizzle in the immediate period, while parts of Delhi and north India are expected to experience rain during the early part of September.
How could below-normal September rainfall affect India?
A weak September monsoon can increase irrigation requirements, affect soil moisture and reduce rainfall-based groundwater and reservoir recharge in some regions. The impact will vary depending on local rainfall, crops, water storage and irrigation facilities.
