Page 19 - SST Class 05

3. Distance from the Sea
Land heats up and cools down quickly. On the other hand, water takes time to heat
and cool. So, the land in coastal areas heats up during the day and cools down at night
quickly. In comparison, the sea water takes time to heat up in the day but it stays

warm for long at night also. This heats up or cools down the air.
The hot air is light, so it rises up. It creates a low pressure area. When the land heats up

quickly during the day, the air over it becomes warm and rises up. To fill this gap, the
air rushes from the sea, which is still cool.
This trend reverses at night. The air over the sea is hot, so it rises creating low pressure
area, so the air from the land rushes to the sea area.

This phenomenon results in winds in the coastal areas. These winds are called breezes.
These winds from the sea and the land are called sea breezes and land breezes

respectively. If you go near the seacoast, you will find the wind blowing all the time.
The tides occur in the sea owing to these breezes.
These breezes moderate the climate near the sea. This is the reason that Kolkata,
Chennai and Mumbai have a moderate climate because they are located near the

seacoast.
The places located away

from the sea have no such
effect, so they have an
extreme climate. So, Delhi
and Chandigarh have an
extreme climate. Extreme
climate means that it is
either too cold or too hot
there.

Know It!

v When the air moves over a water body, it picks up some moisture (water). The amount of moisture
present in the air is called humidity . The monsoon winds bring rain to India as they have come from over
the Indian Ocean.

4. Direction of Winds

If the wind blows from a cold place, it cools; and when it blows from a hot place, it
heats. Similarly, the wind coming from the sea is moist and brings rainfall; on the other
hand, the wind from a dry area dries the area. This is the reason that loo, which blows
from dry and warm areas, dries and heats up the northern plains of our country. The
monsoon winds blow from the sea and bring rainfall.

Weather and Climate 19