Why is morning fog denser near lakes and ORR stretches in Bengaluru? Bengaluru-News News

Last updated:21 January 2026, 14:35 IST

Lakes act like moisture banks. Even in winter, the lake water and the wet soil around it release moisture into the air through evaporation.

At 6:45 am the lake looked peaceful. The road was not built. One minute you could see the bend of the service lane, the next it felt as if someone had drawn a white curtain over the ORR. The headlights turned into soft drops. Auto tail lamps became small red commas. A jogger near the water slowed down, zipped up, and muttered, “The fog is thicker near the lake, no?”

If you travel to Bengaluru, you might have noticed this too. The fog is not spread evenly. It likes certain places. by the lake. Ground level layout. And long, fast stretches like the Outer Ring Road where you’re moving so fast that you realize, oh wow, visibility has just gone down.

What exactly is fog, in simple words

“Fog is basically a cloud that has decided to sit on the ground,” says Dr Krishna Mukund, a Bengaluru-based meteorologist. “It forms when the air near the surface becomes so cold that water vapor condenses into tiny droplets. The easiest time for this to happen is in the morning as the ground cools overnight, especially with clear skies and calm winds.”

If the air becomes saturated, that is, cannot hold any more moisture at that temperature, the water vapor turns into droplets. Those droplets scatter light, and suddenly your world looks like it’s been blurred, he explains further.

Why do lakes make fog denser?

Lakes act like moisture banks. Even in winter, the lake water and the wet soil around it release moisture into the air through evaporation. That extra moisture adds moisture to the surrounding air, making it easier to reach saturation as temperatures drop before sunrise.

There is another effect also. The area around lakes often cools rapidly and remains cold. Cold air is denser, so it settles down. This creates a neat little trap for moisture where you walk, drive, and wait for the bus.

A man strolling along the lake in HSR put it in an illustrative quote: “Near the water, it feels as if there is weight in the air. My glasses fog up before my shoes do.”

ORR Factor, Concrete, Heat and Micro Weather

Fog in ORR parts may increase significantly in Bengaluru. Not because ORR creates fog out of nothing, but because it shapes the way air moves and cools.

Wide roads, flyovers, service lanes and tall buildings create corridors that slow down the air and circulate it unevenly. When winds are light, cool, moist air can persist for long periods of time, especially near underpasses, bus bays and low spots where cold air accumulates.

Then there is the urban heat island effect. The city remains warmer at night than the outskirts because concrete and asphalt store heat and release it slowly. This may seem like it should avoid fog, but it can also create a sharp difference in temperature between the lake shore and the adjacent road corridor. Where moist air suddenly meets a cold surface area, condensation becomes more likely.

An illustrative quote from a traffic constable reflects the reality of commuters: “The fog suddenly becomes thick near some turns and under flyovers. Drivers do not expect it, and that’s when near-misses occur.”

Why do some mornings feel bad?

Fog becomes more dense as these conditions increase:

1. The sky remains clear at night, due to which the heat of the ground decreases rapidly.
2. calm winds, so moist air does not mix
3. High humidity from lakes, wet soil, or even overnight drizzle the day before
4. Cold minimum temperatures, which push the air toward saturation quickly

If you see sporadic, dense fog near lakes and thin fog 2 km away, this is normal. Fog is local. It’s basically hyperlocal weather doing its thing.

What can you do if you travel with these pockets?

Use low beam, not high beam. High beams reflect back fog droplets and make visibility worse. Increase the following distance. Avoid sudden lane changes at turns adjacent to the lake and near the shadow of flyovers. If visibility drops rapidly, slow down slowly and follow lane markings. And if you wear a helmet visor, keep it clean, as fog and dust equal instant fogging.

By 7:20 am the fog cleared, as if it had a schedule. The lake started looking normal again. Orr woke up wide, loud and impatient. The jogger walked near the water the way Bengaluru does after every seasonal wonder.

The fog was never random. It was the moisture of the lake, the cool breeze and a city built in corridors and pockets. The kind of science that’s invisible unless you get right into it.