Heat of Bhadra, a hint of winter in Ashwin

It is a Bhadra afternoon. Outside the window, the sun is scorching the courtyard. The wind is blowing, yet there is no coolness in it. Sweat gathers on the forehead, neck and back. Even under the fan, the air feels hot. To make matters worse, frequent power cuts bring the fan to a halt, and the four walls of the room quickly turn into a heated box. Outside, people wait for the rain; indoors, they wait for relief. Both seem to be taking their time. Adding to the oppressive humidity this year is another uncomfortable message from the global weather system—the El Niño is strengthening.

Yet nature appears to be approaching the final chapter of this spell of heat. From late September, around the middle of Ashwin, temperatures are expected to gradually ease. A gentle coolness will return to the morning air, and in some places, traces of dew will begin to appear. In Panchagarh, the northernmost district of Bangladesh and the part of the country closest to the Himalayas’ Kanchenjunga, the first secret signs of the changing season may be felt in the early morning air. Gradually, that coolness from the north will spread to other parts of the country. The heat of Bhadra, therefore, is not simply heat; hidden within it is the faint tolling of a farewell bell.

In the old saying of rural Bengal, this period was known as Bhadra’s tal-paka heat—the heat that ripens palmyra fruit. The monsoon has not yet completely departed, while autumn has not fully arrived with its boats of white clouds. Sunlight in the sky, rainwater accumulated on the ground and moisture-laden air combine to create a peculiar blanket of warmth.

Meteorologist Tariful Newaz told Views Bangladesh on Monday that the heat of Bhadra is largely a familiar seasonal phenomenon. It was once commonly referred to in rural Bengal as Bhadra’s tal-paka heat. At the tail end of the monsoon, nature seems to bring back a final reminder of summer’s heat.

“This is naturally how it happens. This heat is normally present during this period. As soon as Ashwin arrives, the intensity of the heat will begin to decline. Although it may still feel very hot in direct sunlight, the temperature will feel cooler in the shade. A slight chill will be felt late at night and in the early morning,” he said.

The biggest reason behind this oppressive heat is the abundance of moisture in the air. During the monsoon, vast quantities of water accumulated in canals, wetlands, rivers and other water bodies evaporate under the sun and mix with the atmosphere. Winds blowing over the Bay of Bengal from the south, southeast and southwest also carry large amounts of moisture.

Meteorologist Bazlur Rashid said that when the air contains more moisture, its capacity to retain heat also increases. As a result, the surrounding air itself remains warm. The heat of the sun adds to it. When rainfall decreases even slightly, the familiar humid heat sets in—the kind of heat that offers little relief even in the shade.
“This is part of the normal seasonal cycle. However, as Bhadra comes to an end, towards the end of September, the heat will begin to subside. The sun’s rays will fall more obliquely over the Northern Hemisphere, where Bangladesh is located, so the intensity of sunlight will gradually decrease. Cool winds from the north will then begin to enter the country intermittently. This will reduce the excess moisture in the air and gradually ease the oppressive heat,” he said.

But why does it feel so suffocating now?
The biggest culprit is excessive humidity. During the monsoon, enormous quantities of water accumulated in rivers, canals, wetlands, ponds and other water bodies evaporate under the sun and enter the atmosphere. Winds sweeping across the Bay of Bengal from the south, southeast and southwest also carry huge amounts of moisture.

As a result, the air is not only hot but heavy. Sweat cannot evaporate easily from the body. The natural process through which evaporation of sweat cools the body is disrupted by humid air. That is why the heat can feel considerably more intense than the temperature shown on the thermometer.

Amid this discomfort, however, the prospect of rain offers some relief. According to the Bangladesh Meteorological Department’s forecast, moderate to heavy rainfall may occur in different parts of the country from September 1 to 4. The likelihood of rain may be relatively higher in the Barishal, Chattogram, Sylhet, Rangpur and
Khulna divisions. Dhaka, Rajshahi and Mymensingh may also experience rain accompanied by gusty winds.

When rain arrives, the sun’s intensity is blocked by clouds. Less solar radiation reaches the ground directly, while air movement increases. As a result, daytime temperatures may fall somewhat. But when there is no rain, the combination of moisture and heat can once again bring back the familiar oppressive conditions.
Meanwhile, the El Niño developing in the Pacific Ocean has once again drawn attention. According to the US National Oceanic and Atmospheric Administration’s (NOAA) August assessment, El Niño is strengthening rapidly. There is more than a 90% chance of a very strong El Niño developing during the Northern Hemisphere’s autumn and winter of 2026. There is also a 69% chance that the October-December period could see an El Niño of historic strength among events recorded since 1950.

There is, however, no simple equation suggesting that El Niño itself is the direct cause of every hot day in Bangladesh. But it can significantly alter sea-surface temperatures and atmospheric circulation over the Pacific, potentially influencing the South Asian monsoon and rainfall patterns. A strong El Niño is associated with increased risks of lower rainfall and higher temperatures in parts of Asia. This year, its possible influence on India’s monsoon rainfall has also been noted.
Even so, the clock of the seasons continues to move. Bhadra will give way to Ashwin. As the calendar reaches late September, the first signs of seasonal change will begin to emerge more clearly in nature. In the early mornings of Panchagarh, a thin veil of mist may appear. Dew will gather on the tips of grass. The white glow of Kanchenjunga may still linger over the distant mountains, but the air will carry a different feeling—the winter is coming.

In Kartik, that message will become clearer. By Agrahayan, the nights will grow longer and temperatures will fall. Then, in Poush and Magh, dry, cold winds from the northwest, together with fog, will wrap Bengal in a winter blanket.

So even within the suffocating heat of Bhadra, there is a story of relief. This may not be the final spell of heat, but it could be the last major bout of seasonal discomfort. Ahead lies the gentle doorway of seasonal change. Bhadra, therefore, is not merely the name of a season of intense, humid heat; hidden within it is the first quiet signal that the seasons are about to change.