ScienceCBSE Class 8 · Pressure, Winds, Storms, and Cyclones

Winds, Thunderstorms, Lightning and Cyclones: Class 8 Science

Updated 17 October 2026 · Fact-checked

Wind is air moving from a region of high air pressure to a region of low air pressure; faster winds go with lower pressure. Warm moist air rising creates low pressure, clouds and storms; charge separation in clouds causes lightning and thunder; a cyclone is a spinning system of clouds, winds and rain around a very low-pressure eye that forms over warm ocean water.

Wind always blows from high pressure to low pressure: by day warm land air rises so wind comes from the sea, and at night it reverses.

Illustration drawn for QuestionBuddy.

Understand Winds, Thunderstorms, Lightning and Cyclones

Formation of wind. In Activity 6.5 two balloons joined by a straw, one inflated and one not, show that air moves from the higher-pressure balloon to the lower-pressure one, until the pressures become equal and the flow stops. So air moves from a region of high pressure to a region of low pressure; the speed is greater when the pressure difference is greater. Sea breeze and land breeze are examples. By day land heats faster than water, the air over land becomes warm and lighter, rises and leaves low pressure, and wind blows from the high-pressure sea to the land (sea breeze). At night the water is warmer, low pressure develops over the sea and wind blows from land to sea (land breeze).

Fast winds lower air pressure. Blowing between two hanging balloons makes them move toward each other, because a low-pressure area forms between them and the higher pressure around pushes them in. Hence high-speed winds are accompanied by reduced pressure. Over a house the pressure above the roof falls, so if the pressure difference is large and the roof is weak, the roof can be blown away. Keeping doors and windows open in a storm reduces the difference between inside and over the roof.

Storms and thunderstorms. Heated land makes warm, moist air rise, forming low pressure; cooler air rushes in and the cycle continues. The rising air expands and cools, vapour condenses into droplets and clouds, and rain, hail or snow falls. Strong winds with rain form a storm; storms are frequent in hot, humid, tropical regions like India. Higher up, droplets turn to ice particles. Updraughts and downdraughts rub them against one another and static charges develop: the lighter positively charged ice particles gather in the upper part of the cloud and the heavier negatively charged droplets in the lower part. The negatively charged base makes the ground, trees and buildings below positively charged. Air is normally an insulator, but when the charge grows very large it breaks down and charges flow suddenly, producing lightning. Lightning heats the air around it so rapidly that the air expands and produces thunder. A storm with lightning and thunder is a thunderstorm. Local thunderstorms have names such as Kalboishakhi (West Bengal, Bihar, Jharkhand), Bordoisila (Assam) and mango showers (Kerala, Karnataka, Tamil Nadu).

Lightning safety. Stay away from tall objects; go to a low open area and crouch down, minimising contact with the ground, not lying flat; avoid an umbrella with a metal rod; get out of water; a bus or car is comparatively safer. A lightning conductor is a metal rod along the wall of a building with a pointed end above the highest point and the other end buried deep in the ground, giving the charges an easy path to the ground.

Cyclones. A cyclone forms over warm ocean water. Warm moist air rises; vapour condenses; heat is released, warming the air further so it rises further and the pressure falls even more. Air from the surroundings rushes in and rises as well, and the Earth's rotation makes the moving air spin. The result is a very low-pressure area with high-speed winds revolving round it. The central region of lowest pressure is the eye, where the wind is calm, while the surrounding region has strong winds and heavy rain. Over land the supply of moist air is cut off and the cyclone weakens. The chapter gives Amphan (2020) with peak winds of 270 km/h as an example of destruction.

Effects and safety. Strong winds push ocean water toward the shore, forming a wall of water 3 to 12 metres high (storm surge); heavy rain causes floods and landslides; seawater contaminates drinking water and reduces soil fertility; trees and debris block roads; power cuts can last days. Stay updated on alerts from the India Meteorological Department (IMD), keep an emergency kit and move to a designated cyclone shelter. Satellites help track cyclones and predict their path.

The previous topic covers pressure in solids, liquids and air.

Winds, Thunderstorms, Lightning and Cyclones: formulas and key facts

Direction of wind: High pressure region > low pressure region; Greater pressure difference means faster wind.
Sea breeze and land breeze: Day: sea to land | Night: land to sea; Land heats and cools faster than water.
Fast wind and pressure: Higher wind speed > lower air pressure; Why roofs can be blown off.
Lightning sequence: Rubbing in cloud > charge separation > air breakdown > lightning > heated air expands > thunder; Lightning conductor leads charge to the ground.
Cyclone structure: Eye: lowest pressure, calm | Surrounding: strong winds, heavy rain; Forms over warm ocean; weakens over land.
Pressure units for weather: $1 mb = 1 h P a = 100 P a$; Cyclone figure shows 994 mb at the centre.

How to solve Winds, Thunderstorms, Lightning and Cyclones questions

Use this method for weather questions.

1Mark which region has higher and which has lower pressure; wind goes from high to low.
2Decide which surface heats faster (land by day, sea by night) to find which has the low pressure.
3For storms, follow: warm moist air rises, expands, cools, condenses, rain.
4For lightning, list rubbing, charge separation, breakdown of air and thunder.
5For cyclones, start at warm ocean water and end with the calm eye.
6For safety, give the right action: low open place, no metal umbrella, move to a shelter.

Winds, Thunderstorms, Lightning and Cyclones in real life

Each concept, met in an everyday situation. Read the situation, try the problem, then check the solution. The one-line hook is what to remember.

Reading a pressure map

Suppose a weather map marks places P, Q and R with pressures 1008 mb, 998 mb and 994 mb (the same values as the chapter's cyclone figure).

(a) In which direction does the wind blow between P and R? (b) Find the pressure difference between P and R in mb and in Pa. (c) Which place is nearest the eye of the cyclone? (d) Where is the wind fastest, between P and Q or between Q and R, if P-Q and Q-R are equally far apart?

Try it first, then show the solutionSolution

From P (high pressure) to R (low pressure).
1008 − 994 = 14 mb; 14 × 100 = 1400 Pa.
R has the lowest pressure, so it is nearest the eye (the centre).
P-Q difference = 10 mb; Q-R difference = 4 mb. The bigger difference gives faster wind, so between P and Q.

Answer: (a) P to R; (b) 14 mb = 1400 Pa; (c) R; (d) between P and Q.

Memory hook: Steeper pressure slope, stronger wind.

Sea breeze day and night

Imagine a coastal town where the afternoon wind blows in from the sea but the early-morning wind blows out to the sea.

(a) Name each wind. (b) Why does the afternoon wind blow from the sea? (c) Why does it reverse at night?

Try it first, then show the solutionSolution

Afternoon: sea breeze. Early morning: land breeze.
By day the land heats faster than the water; air over land becomes warm and lighter, rises and creates low pressure; wind flows from the high-pressure sea.
At night the water is warmer than the land, so low pressure develops over the sea and the wind blows from land to sea.

Answer: (a) Sea breeze and land breeze; (b) low pressure over the heated land; (c) low pressure over the warmer sea at night.

Memory hook: Wind runs toward the lower pressure.

Tricks to remember Winds, Thunderstorms, Lightning and Cyclones

Short memory aids. Say each one aloud once, then use it on a question the same day.

High to Low, Hill to Valley
Think of air rolling from a pressure hill to a pressure valley.
Use it when: Direction of wind.
Light before sound
Lightning is the flash; thunder is the sound of heated air expanding.
Use it when: Lightning and thunder.
Eye is calm, edge is violent
A cyclone eye is lowest pressure and calm; the ring round it has the fiercest winds.
Use it when: Cyclone structure.

Winds, Thunderstorms, Lightning and Cyclones: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Why does wind blow · 3 marks · Short answerBoard level

Explain with an activity why wind blows, and state the direction of air movement.

Try it first, then show the solutionSolution

Join an inflated balloon to an uninflated one with a straw. (1)
Air flows from the inflated (high pressure) balloon to the uninflated one until pressures become equal. (1)
So wind blows from a region of high pressure to a region of low pressure. (1)

Answer: Air moves from high pressure to low pressure; the balloons show this until the pressures are equal.

Example 2: Safest place in lightning · 1 mark · MCQBoard level

During a thunderstorm, which is the safest place?
(a) Under a tall tree
(b) In a pond
(c) Inside a bus or car
(d) Holding a metal-rod umbrella in an open field

Try it first, then show the solutionSolution

The chapter says a closed bus or car is comparatively safer; tall objects, water and metal umbrellas are dangerous.

Answer: (c)

Example 3: How a thunderstorm gives lightning and thunder · 5 marks · Long answerHarder board level

(a) How do charges build up in a thundercloud? (2) (b) Why does lightning occur if air is an insulator? (1) (c) Why does thunder follow? (1) (d) Give two safety rules and one device that protects buildings. (1)

Try it first, then show the solutionSolution

(a) Strong winds moving up and down rub water droplets against ice particles; lighter positively charged ice particles go to the top and heavier negatively charged droplets to the bottom of the cloud, separating the charge. (2)
(b) When the charge becomes very large the insulating property of air breaks down and charges flow suddenly, giving a flash. (1)
(c) The flash heats the air rapidly, which expands and produces a loud sound. (1)
(d) Stay away from tall objects, crouch in a low open area; a lightning conductor on buildings. (1)

Answer: Rubbing separates charges; breakdown of air gives lightning; sudden heating gives thunder; stay low and use a lightning conductor.

Example 4: Why a roof lifts in a storm · 4 marks · Case-basedHarder board level

Read the passage and answer.

During a storm a weak roof is blown off a house while the windows are shut.
(a) Compare the air pressure above and below the roof. (1)
(b) Give the activity that supports your statement. (1)
(c) Why does keeping doors and windows open help? (1)
(d) A bigger pressure difference of 300 Pa acts on a roof of area 40 m2; find the net upward force. (1)

Try it first, then show the solutionSolution

(a) Pressure above is lower because fast wind lowers air pressure, so higher pressure below pushes the roof up. (1)
(b) Blowing between two balloons makes them move toward each other. (1)
(c) Wind goes through the house, reducing the difference between inside and over the roof. (1)
(d) F = P × A = 300 × 40 = 12 000 N. (1)

Answer: (a) Lower above; (b) balloons activity; (c) pressure difference decreases; (d) 12 000 N.

Example 5: Cyclone: why it fades on land · 4 marks · Case-basedHOTS / competency

Read the passage and answer.

A cyclone forms over warm ocean water with a central pressure of 940 mb while the surrounding pressure is 1010 mb. After landfall it slowly weakens.
(a) Find the pressure difference in mb and in Pa. (1)
(b) Explain why air spirals inwards and spins. (1)
(c) Why does it weaken on land? (1)
(d) A wall of water 5 m high travels toward the shore; name the hazards it creates. (1)

Try it first, then show the solutionSolution

(a) 1010 − 940 = 70 mb; 70 × 100 = 7000 Pa. (1)
(b) Air rushes from high-pressure surroundings to the low-pressure centre and the Earth's rotation makes it spin. (1)
(c) On land the supply of warm moist air from the ocean is cut off. (1)
(d) Flooding of coasts, contaminated drinking water, loss of soil fertility. (1)

Answer: (a) 70 mb = 7000 Pa; (b) high to low pressure plus Earth's rotation; (c) no moist air supply; (d) flooding, contaminated water, less fertile soil.

Where students lose marks in Winds, Thunderstorms, Lightning and Cyclones

The slips examiners see most often, and what to write instead.

Mistake: Saying wind blows from low to high pressure.
Mixing up the direction.
Wrong working
Air moves from a region of low pressure to high pressure.
Right working
Air moves from a region of high pressure to a region of low pressure.
Do this: Picture a punctured tyre: air leaves the high-pressure side.
Usually costs: 1 mark.
Mistake: Saying the sea has low pressure by day.
Water is thought to be hotter.
Wrong working
By day, low pressure forms over the sea.
Right working
By day, land heats faster, so low pressure forms over the land and the sea breeze blows in.
Do this: Land heats and cools faster.
Usually costs: 1 mark.
Mistake: Describing the eye of the cyclone as the windiest part.
The centre sounds the most intense.
Wrong working
The eye has the strongest winds.
Right working
The eye is calm with the lowest pressure; the strong winds and heavy rain are in the region around it.
Do this: Calm centre, fierce ring.
Usually costs: 1 mark.
Mistake: Giving unsafe lightning advice.
People shelter under trees or lie flat.
Wrong working
Lie flat or stand under a tall tree.
Right working
Stay away from tall objects, crouch in a low open area and do not lie flat; avoid metal umbrellas and water.
Do this: Use the book's list.
Usually costs: 1 mark.

Exam tips

Always state wind direction as 'from high pressure to low pressure'.
For sea and land breeze, name which surface heats faster and where the low pressure forms.
For lightning, give the order: rubbing, charge separation, breakdown of air, flash, thunder.
For cyclones, include warm ocean, condensation heat, low pressure, spin due to the Earth's rotation and the calm eye.
Quote figures as in the chapter: 994 mb, 3 to 12 m, 270 km/h (Amphan 2020).

Practice questions on Winds, Thunderstorms, Lightning and Cyclones

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 2 marks · Very short answerBoard level
What is a lightning conductor and how does it protect a building?
Hint
Pointed end up, other end underground.
Answer
A metal rod fixed along a wall, with a pointed end above the building and the other end buried deep in the ground (1); it gives the electric charge an easy path to the ground (1).
Q2 · 1 mark · MCQBoard level
The calm region at the centre of a cyclone is called
(a) the core of the cloud
(b) the eye
(c) the funnel
(d) the front
Hint
Lowest pressure, calm winds.
Answer
(b)
Q3 · 1 mark · Assertion-reasonHarder board level
Assertion (A): A sea breeze blows during the day.
Reason (R): Land heats faster than water, so a low-pressure area forms over the land.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Hint
Which way does wind go?
Answer
(a) R explains why wind goes from the sea to the land.
Q4 · 4 marks · Short answerHarder board level
A weather chart shows 1012 mb at the sea and 1002 mb at an inland place 50 km away, and 996 mb at a place 25 km beyond. (a) Which direction does the wind blow? (b) Find the pressure difference from the sea to the farthest place in Pa. (c) Which stretch has the larger pressure gradient per km: sea to inland, or inland to farthest? (d) Where would the wind be stronger?
Hint
Divide mb difference by km.
Answer
(a) From the sea toward the lower pressure inland. (b) 1012 − 996 = 16 mb = 1600 Pa. (c) Sea to inland: 10 mb over 50 km = 0.2 mb/km; inland to farthest: 6 mb over 25 km = 0.24 mb/km, so the second is larger. (d) The wind is stronger on the second stretch, where the pressure changes faster (1 mark each).
Q5 · 4 marks · Case-basedHOTS / competency
Read the passage and answer.
A family keeps all windows closed during a cyclone alert and the roof is damaged. Another family keeps some windows open. Both were told to follow IMD alerts and move to a shelter.
(a) Explain how the wind can damage the roof. (b) Why did the open windows help? (c) Name two other preparations for a cyclone. (d) Why do cyclones weaken after they reach land?
Hint
Think of pressure above the roof and inside the house.
Answer
(a) Fast wind lowers pressure over the roof, so higher pressure below pushes the roof up. (b) They reduce the pressure difference between inside and outside. (c) Keep an emergency kit; check weather alerts; move to a cyclone shelter. (d) The source of moist air is cut off (1 mark each).

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.In which direction does wind blow?Show answer
From a high-pressure region to a low-pressure region.
2.What happens to air pressure when wind speed is high?Show answer
It decreases.
3.What causes thunder?Show answer
Rapid heating and expansion of air by lightning.
4.Where does a cyclone form?Show answer
Over warm ocean water.
5.Which agency issues cyclone alerts in India?Show answer
The India Meteorological Department (IMD).
6.What is the height of the wall of water in a cyclone according to the chapter?Show answer
3 to 12 metres.

Winds, Thunderstorms, Lightning and Cyclones: frequently asked questions

Why do the balloons come closer when we blow between them?

Blowing creates a low-pressure area between them, and the higher pressure around pushes them together.

Is it safe to stand in an open field during lightning?

The chapter says to stay away from tall objects and find a low-lying open area, crouching down without lying flat.

Why are storms frequent in India?

The chapter says storms are more frequent in hot, humid, tropical regions such as India.

How do satellites help in cyclones?

They monitor cyclones so that their path can be predicted and people can be warned.