A glance at a satellite image of India this week presents an unusual picture. By the second week of July, the southwest monsoon is typically at its peak. Thick cloud bands usually blanket the Arabian Sea, the Bay of Bengal remains highly active with rain-bearing systems, and the Western Ghats are almost continuously covered by dense cloud and heavy rainfall.
Instead, current satellite imagery shows largely clear skies over the Arabian Sea and much of the Bay of Bengal, while central India appears unusually cloud-free. The scene resembles conditions usually seen in April, before the onset of the monsoon, rather than during its most active phase in July.
This is not a satellite malfunction but a recognised feature of the Indian monsoon known as a "break", a temporary pause in widespread rainfall.
On July 10, the India Meteorological Department (IMD) stated that rainfall activity over central and south peninsular India is expected to remain subdued for the next six to seven days.
In effect, the core monsoon region has entered a quiet phase that is likely to continue until around July 17.
The timing has raised concern because the pause follows one of the driest Junes recorded in more than a century and comes after only a brief spell of widespread rainfall during the first week of July.
What satellite images reveal
Weather satellites such as ISRO's INSAT-3DR and INSAT-3DS continuously monitor India's weather using both visible-light and infrared imaging.
Infrared imagery is particularly useful because it detects the temperature at the tops of clouds. Very cold cloud tops indicate deep convective clouds, which develop when warm, moisture-laden air rises rapidly into the atmosphere. These towering cumulonimbus clouds are responsible for heavy rainfall.
During the first week of July, satellite images showed two major cloud systems dominating the region. One developed over the east-central Arabian Sea, supplying moisture to the Konkan coast and the Western Ghats, while another formed over the northern Bay of Bengal, bringing widespread rain to eastern India.
This week, however, both systems have weakened significantly. Instead of extensive deep cloud cover, only scattered and relatively shallow clouds remain over the seas and much of the Indian mainland.
This absence of deep convection explains why current satellite images resemble those of April rather than the peak monsoon season.
The monsoon has shifted, not failed
Meteorologists attribute the present lull primarily to the position of the monsoon trough, an elongated zone of low atmospheric pressure that usually stretches across northern and central India.
The trough normally acts as a corridor that draws moisture from both the Arabian Sea and the Bay of Bengal, forcing the moist air to rise and produce widespread rainfall over central India.
However, the monsoon trough periodically shifts northwards towards the Himalayan foothills during every monsoon season.
According to the IMD's extended-range forecast covering July 9 to July 22, the western end of the trough has moved close to or north of its normal position.
This shift has dramatically altered the rainfall distribution.
Regions along the Himalayan foothills, northeast India, Bihar and eastern Uttar Pradesh are receiving substantial rainfall, while central and peninsular India have been left under descending, or subsiding, air.
Subsiding air warms and dries as it sinks, suppressing cloud formation instead of encouraging it.
Although surface humidity remains high, creating muggy conditions, the atmosphere lacks the upward motion necessary for rain-bearing clouds to develop.
The missing weather systems from the Bay of Bengal
Another reason for the current dry spell is the absence of low-pressure systems over the Bay of Bengal.
Throughout a normal July, the Bay regularly produces low-pressure areas and depressions that travel inland across Odisha, Chhattisgarh, Madhya Pradesh and neighbouring states, carrying enormous amounts of moisture into central India.
These systems are the primary source of widespread rainfall over the country's interior.
The heavy rains experienced during the first week of July were generated by one such depression that formed over the northwest Bay of Bengal on July 5 before moving across Odisha, Jharkhand and Madhya Pradesh.
At present, however, no new low-pressure system has formed to replace it.
As a result, the primary mechanism supplying rainfall to central India has temporarily weakened.
The Arabian Sea branch of the monsoon has also become less active.
The low-level jet—a powerful stream of southwesterly winds that transports moisture across the Arabian Sea towards the Western Ghats—has weakened.
Since the Western Ghats generate rainfall by forcing these moist winds to rise over the mountains, weaker winds have reduced rainfall along India's west coast as well.
Global climate factors are also playing a role
Meteorologists say broader climate patterns are reinforcing the present break in the monsoon.
One contributing factor is El Niño, characterised by unusually warm sea surface temperatures across the central and eastern Pacific Ocean.
El Niño alters atmospheric circulation across the tropics, shifting rising air towards the Pacific while encouraging descending air over regions including the Indian subcontinent.
According to the IMD, weak El Niño conditions currently prevail and are expected to continue through much of the southwest monsoon season.
These conditions contributed to June ending with a rainfall deficit of around 40 per cent, making it one of the driest Junes since records began in 1901.
Another important influence is the Madden-Julian Oscillation (MJO), a large-scale tropical weather pattern that circles the globe every 30 to 60 days.
The MJO enhances rainfall wherever it is located while suppressing rainfall elsewhere.
The IMD noted that the MJO is presently in Phase 8, a position generally associated with reduced rainfall over India.
Meanwhile, the Indian Ocean Dipole (IOD), another climate pattern that can sometimes offset the effects of El Niño by increasing moisture over India, remains in a neutral phase this year, offering little additional support to the monsoon.
When is rainfall expected to return?
The outlook for the second half of July is more encouraging.
According to the IMD's extended-range forecast for July 16 to July 22, the western end of the monsoon trough is expected to gradually return towards its normal position.
More significantly, meteorologists anticipate the formation of a cyclonic circulation over the northwest Bay of Bengal, which is likely to develop into a fresh low-pressure area during the first half of that week.
If this system forms and moves inland, it should pull the monsoon trough southward once again and restore moisture transport into central India.
The IMD expects this to result in more widespread rainfall, including isolated spells of heavy to very heavy rain across central India, the west coast and several other regions.
Until then, much of central, western and peninsular India is likely to experience largely clear skies, prolonged sunshine, rising daytime temperatures and uncomfortable humidity, with moisture trapped near the surface increasing the "feels-like" temperature despite the lack of rainfall.
Why this break is significant
Temporary breaks are a normal part of the Indian monsoon, with most seasons experiencing two to four such pauses.
However, this year's break has drawn greater attention because it follows an exceptionally dry June.
The southwest monsoon reached Kerala on June 4 and covered the entire country by July 9, only a day behind its normal schedule.
Despite this, June rainfall remained around 40 per cent below normal, and the brief wet spell in early July only partly reduced the seasonal deficit.
By July 8, cumulative monsoon rainfall stood at 195.5 mm against the long-period average of 230.4 mm, representing a deficit of approximately 15.2 per cent.
The IMD's monthly outlook also projects below-normal rainfall for July, with national rainfall expected to remain below 94 per cent of the month's long-term average of around 280.4 mm.
The timing is particularly important for agriculture.
Kharif crops such as rice, cotton, soybean and maize are currently in their early growth stages and require consistent rainfall.
A prolonged dry spell at this stage can stress young plants, slow reservoir replenishment and delay groundwater recharge, particularly in rain-fed agricultural regions.
A short break of about a week is generally manageable.
However, the next phase of the monsoon will depend heavily on whether the anticipated low-pressure system develops over the Bay of Bengal.
If it does, the present pause is likely to be remembered as a temporary interruption.
If it fails to materialise, the rainfall deficit following one of the driest Junes on record could become considerably more severe.
