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September 10, 2025 - Severe Summer Monsoon Floods the Ganges River
September 1, 2025
August 22, 2025
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Water in the Ganges (Ganga) River sweeps across more than 2,500 kilometers (1,550 miles) as it travels from the river’s source at the terminus of the Gangotri Glacier in the Himalaya mountains, traverses India, and finally spills into the Bay of Bengal. Many tributaries, which originate in high regions of Nepal, Bangladesh, and the Tibetan Plateau, flow into the Ganges along the river’s long course. In addition to glacier melt and the contribution of the tributaries, the depth of the Ganges also relies on rainfall brought by the southwest monsoon.
The southwest monsoon, also known as the Indian summer monsoon, is the strongest and perhaps best-known of the world’s monsoons. During summer months when the Asian landmass heats up, warm, moist air flows northward from the Indian Ocean towards the Himalayas, bringing abundant showers and thundershowers to India. The summer monsoon is a regular event that occurs every year and is responsible for roughly 80% of India’s annual rainfall. The summer monsoon typically starts in early June, peaks in July and August and winds down during September and early October.
The 2025 summer monsoon has been exceptionally strong and, in early August, helped trigger flooding in Uttarakhand, a state in northern India. The flash flood in that region was blamed for the deaths of at least five people. News media also reports that flooding from monsoonal rains has created severe flooding and landslides in northern India in late August and early September, with at least 90 people killed by September 4. Monsoonal flooding in Punjab state has killed livestock, destroyed crops, and is being blamed for at least 30 deaths.
The heavy rains also filled the Ganges to flood stage. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured a pair of false-color images that, taken together, show the extent of the monsoon on the Ganges River and the extreme rise of the river between August 22 and September 1. This type of image helps distinguish water (dark blue) from vegetation (bright green) and open land (tan). Clouds typically appear white but high, cold clouds that contain ice may show a trace of light electric blue.
The top image, acquired on September 1, 2025, shows the Ganges River and several tributaries in flood stage. The Ganges, which flows on a roughly west-to-east axis in this image, appears extremely wide and has spilled onto the flood plain, especially in the eastern section. The tributaries to the north (the Ghaghara, Gandaki, and Kosi Rivers) and from the south (the Sone River) are also very wide.
The second image, acquired on August 22, 2025, can be viewed by clicking on the date. Even though the monsoon had been active for weeks and flooding had brought extra water into all the rivers, the impression is very different from September 1. In this image, the Ganges River looks like a thin blue line, compared to the wide swath of September 1, as do all the other tributaries. The dramatic change in river height in a mere ten days was triggered by torrential monsoonal rains.
Image Facts
Satellite:
Terra
Date Acquired: 9/1/2025
Resolutions:
1km (182.3 KB), 500m (416.8 KB), 250m (268.6 KB)
Bands Used: 7,2,1
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
September 1, 2025 August 22, 2025
Water in the Ganges (Ganga) River sweeps across more than 2,500 kilometers (1,550 miles) as it travels from the river’s source at the terminus of the Gangotri Glacier in the Himalaya mountains, traverses India, and finally spills into the Bay of Bengal. Many tributaries, which originate in high regions of Nepal, Bangladesh, and the Tibetan Plateau, flow into the Ganges along the river’s long course. In addition to glacier melt and the contribution of the tributaries, the depth of the Ganges also relies on rainfall brought by the southwest monsoon.
The southwest monsoon, also known as the Indian summer monsoon, is the strongest and perhaps best-known of the world’s monsoons. During summer months when the Asian landmass heats up, warm, moist air flows northward from the Indian Ocean towards the Himalayas, bringing abundant showers and thundershowers to India. The summer monsoon is a regular event that occurs every year and is responsible for roughly 80% of India’s annual rainfall. The summer monsoon typically starts in early June, peaks in July and August and winds down during September and early October.
The 2025 summer monsoon has been exceptionally strong and, in early August, helped trigger flooding in Uttarakhand, a state in northern India. The flash flood in that region was blamed for the deaths of at least five people. News media also reports that flooding from monsoonal rains has created severe flooding and landslides in northern India in late August and early September, with at least 90 people killed by September 4. Monsoonal flooding in Punjab state has killed livestock, destroyed crops, and is being blamed for at least 30 deaths.
The heavy rains also filled the Ganges to flood stage. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured a pair of false-color images that, taken together, show the extent of the monsoon on the Ganges River and the extreme rise of the river between August 22 and September 1. This type of image helps distinguish water (dark blue) from vegetation (bright green) and open land (tan). Clouds typically appear white but high, cold clouds that contain ice may show a trace of light electric blue.
The top image, acquired on September 1, 2025, shows the Ganges River and several tributaries in flood stage. The Ganges, which flows on a roughly west-to-east axis in this image, appears extremely wide and has spilled onto the flood plain, especially in the eastern section. The tributaries to the north (the Ghaghara, Gandaki, and Kosi Rivers) and from the south (the Sone River) are also very wide.
The second image, acquired on August 22, 2025, can be viewed by clicking on the date. Even though the monsoon had been active for weeks and flooding had brought extra water into all the rivers, the impression is very different from September 1. In this image, the Ganges River looks like a thin blue line, compared to the wide swath of September 1, as do all the other tributaries. The dramatic change in river height in a mere ten days was triggered by torrential monsoonal rains.
Image Facts
Satellite:
Terra
Date Acquired: 9/1/2025
Resolutions:
1km (182.3 KB), 500m (416.8 KB), 250m (268.6 KB)
Bands Used: 7,2,1
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
