Climate of pakistan

1. Climate of Pakistan

2. Weather and climate
• Climate:
Climate describes the temperature, precipitation, and
other weather conditions of a certain area. The climate of
an area describes how these variables may be over a long
period, for instance the South of France in the summer is
hot and dry.
• Climate is permanent
• It prevails in all region
• It changes the seasons
• Weather: However this is not always the case as there are
some days when it is raining and fairly cools. These daily
changes do not affect the overall climate of the area, and
are described as the weather of the area for that day.
• Weather is temporary
• It varies from place to place

3. Factors Effecting Climate of an Area
• Altitude: Temperature falls the higher you are.
The loss in temperature is approximately 10°C
for every kilometer you rise. This fall in
temperature with height is due to the fact that
the air at higher altitudes is thinner. There are
fewer molecules available to receive and retain
heat. Wind chill may also mean that the
temperatures in upland areas are lower than
expected.

4. Factors Effecting Climate of an Area
• Distance from the Sea: The sea can have agreat
influence over climates in maritime regions. The sea
takes much longer to heat up but retains that heat far
better than the land. Consequently the land is often
warmer than the sea during the day, however the
situation is reversed at night.
• Explanation: This means that places like Karachi, which
are near the sea, have relatively cool days and warm
nights, as well as warm summers and mild winters. The
influence of the sea diminishes as you move further
inland, for instance to central Europe, where warmer
winters and cooler summers will be experienced.

5. Factors Effecting Climate of an Area
• Latitude: on global climates. Lines of Latitude are those that run
horizontally around the world. The most famous line of latitude is the
Equator. Using the lines of latitude we can easily divide the world in to
specific climatic sections.
• Explanation: Between 23.5 South and 23.5 North is the region called
the Tropics. These receive the most heat from the sun because it is
almost directly overhead and so the solar radiation does not have to
travel through very much of the atmosphere. It heats a very
concentrated area of the surface of the ground.
• Between 23.5 and 66.5 in both the Northern and Southern
Hemispheres are the Temperate regions. These have reasonably hot
summers and mild winters.
• Above 66.5 in both hemispheres are the Polar Regions, which are very
cold. They receive sunlight for only half the year due to the angle of the
Earth on its rotation. During the months when they do have sunlight, it
travels to them at a very shallow angle, meaning that it has to travel
through a lot of the atmosphere and has to heat a wide area of the
surface.

6. TEMPERATURE IN PAKISTAN

7. TEMPERATURE IN PAKISTAN

8. Factors Effecting Climate of an Area
• Ocean Currents: Many areas beside the sea are
affected by ocean currents. These can be either
warm or cold currents.
• Explanation : The United Kingdom is directly in
the path of the Gulf Stream and the Northern
Atlantic Stream, which bring warm water from
the Caribbean across the Atlantic to our shores.
This current alone is the reason why our climate
is mild compared to places of similar latitude like
Newfoundland.

9. HIGHER ALTITUDES EXPERIENCE VERY LOW TEMPERATURE

10. Factors Effecting Climate of an Area
• Prevailing Winds: The prevailing (most common)
wind in the United Kingdom comes form the
South West. If a prevailing wind travels over a
warm surface it will bring warm weather, whilst if
it travels over a cold surface it will bring cold
weather.
• Explanation: The south-westerly winds in Britain
travel across the Atlantic. In the summer this
means that the air is cooled, whilst in the winter
the water warms the air, bringing warmer w

11. Temperature in Pakistan
• The sun is the main source of temperature changes in the air.
• Temperatures vary due to Altitude, Latitudinal effect, Oceanic influence continental effects.
• Those parts of the earth are warmer which receive direct vertical rays of the sunlight than those which
receive slanting rays.
• The sun shines vertically at places lying between the Tropics of Cancer (23.5 N Latitude) and Capricorn
(23.5 S Latitude).
• Types of Temperature
• Mean Maximum Temperature
• Mean Minimum Temperature
• Diurnal or daily temperature
• Annual Temperature
• Temperature is measure in C or F
• The lines connect the areas having similar temperatures are called ISOTHERMS
• Reasons for Variation in Temperature in Pakistan.
• Latitudinal Effect: Pakistan Lies near the Tropic of Cancer therefore, it records higher temperatures due
to latitudinal effects
• Altitudinal Effect: The mountains experience mild temperature in summer and very cold in winter .
• Oceanic Influence: The coastal areas have moderate temperatures through the year because of oceanic
influence
• Continental Effect: Terrestrial radiation / convection of earth makes the temperatures high in Indus plains
and Balochistan Plateau.
• Sibbi (Balochistn) Jaccobabad (Sindh) and Multan(Punjab) are the hottest places of Pakistan
• The mean maximum temperature was recorded in Sibbi
• The minimum temperatures are recorded in the months of Dec-Jan in Northern Mountains and Quetta.

12. Types of Temperature
Categories of Temperature Degree of Temperature
Hot 32 ⁰C or more
Warm 21 ⁰C to 31 ⁰C
Mild 10 ⁰C to 20 ⁰C
Cool 0 ⁰C to 9 ⁰C
Cold Below 0 C⁰

13. Record Breaker: Temperature and Precipitations Estimates in
Pakistan
Factors Record
Highest Temperature 53 ⁰C at Jacobabad on 12 June 1919
Lowest Temperature -16⁰C at Chitral on 27 December 1695
Highest Annual Precipitation 2560.8 millimeters at Murre in 1914
Lowest Annual Precipitation No precipitation at Lasbela in 1971; Sibi in 1973; Kalat
in 1981; Karachi, Nawabshah and Badin in 1987. No
precipitation at Sukkur and Jiwa ni recorded over
several years.

14. Air Pressure and Winds In Pakistan
• The amount of humidity in the air causes air pressure.
• Air pressure is measured in inches, centimeters and millibars by an instrument known
as BAROMETER.
• The air pressure is shown on map by a line which is called ISOBAR.
• ISOBAR connects the areas experience the same air pressure.
• Factors effecting Air Pressure
• Height/ Altitudinal effect
• Distance from the sun / Latitudinal effect
• Distance from the sea/ oceanic Influence
• Reasons for difference of Air Pressure in Pakistan
• Temperature : Air pressure rises when temperature decrease. It decrease when
temperature rises. Air pressure is high in winter and low in summer.
• Height : the air pressure rises in the highlands due to moisture in the air
• Oceanic Influence: The amount of humidity is relatively very high near the sea so air
pressure is high.
• Continental Effect; Air pressure decreases in the Indus Plains, Deserts and
Balochistan Plateau due to continental effect.
• Effects of Air Pressure
• Intense low air pressure areas can cause serious storms (Cyclones) Monsoon Winds,
Western Depressions are its example in Pakistan.

15. Air Pressure and Winds In Pakistan
• In summers, air pressure remains low throughout
Pakistan. One of the most important result are
the Monsoon.
• In summers, Sindh becomes the lowest pressure
area in the world.
• In winter, two events take place: a high pressure
belt develops over central Asia leading to cold
winds; Pakistan is affected by the western
disturbances which something bring rainfall.

16. Types of Rainfall in Pakistan
• There are four sources of rainfall in Pakistan
• Monsoon Rainfall
• Western Depressions
• Convectional Rainfall
• Relief Rainfall
• The rainfall is measured by rain guage in
centimeters, inches or millimeters.
• The line marks the areas experience same
amount of precipitation is called ISOHYTES

17. Rising Air Phenomenon
• As air rises it cools it cannot hold as much
moisture as it could when it was warmer.
Eventually the rising air reaches a point where it
is 100% saturated, in other words it cannot hold
any more water. This is called dew point, and it is
above this point that condensation occurs.
• Condensation is the process by which the water
vapour (a gas) held in the air is turned back into
water droplets (a liquid), which fall as rain.

18. The Monsoon winds
• The word monsoon means a season
• The monsoon winds originate in Bay of Bengal
and Arabian sea due to rising air phenomenon
• They are of two types.
A – Summer Monsoon
(from sea to land –July to August )
B- Winter Monsoon
( from land to sea-November to January)

19. How Does Monsoon Originate?
• In summer, the temperature rises on the land
surface while the sea water remains
comparatively cool due to oceanic influence.
• The rising temperature creates builds a low air
pressure on the land
• The Arabian sea and Bay of Bengal experience
high pressure due to relatively high humidity.
• The wind blows from sea to land to fill the
vacuum created because of low air pressure.
• The winds originate in Arabian sea and Bay of
Bengal in July August.

20. Monsoon Rainfall in Pakistan
July to September
• Pakistan receives the tail end of the Monsoon winds.
• They enter Pakistan from south east after crossing India.
• They usually enter Pakistan in July and last till September.
• Since they enter from east, so eastern part of Pakistan
receives more rainfall.
• The main Monsoon winds enter northern Punjab, with the
secondaries entering southern Punjab and Sind.
• The amount of rainfall decrease sharply from North to
South.
• Murree receives 813 mm (Highest) Nokandi 2.5
mm(Lowest)

21. Why is Monsoon rainfall not effective for Pakistan?
• Monsoon rainfall is of pulsating nature.
• The rainfall occurs in torrents.
• The rainfall occurs in heavy showers that
sometimes causes flood.
• The water seepage ratio is low
• Generally rainfall happens with long dry spells in
between.
• The number of rainy days are only 10 to 20 days
annually.
• North and South Pakistan receives this rainfall.

22. Western Depression - December to March
• The Western Depressions originate in the
Mediterranean sea due to low air pressure on the
land and high air pressure on the sea.
• The tail end of the Western Depressions enter
Pakistan after crossing Turkey, Iraq, and Iran.
• They are robbed off most of their moisture on the
long land journey so they bring a small amount of
rainfall to Pakistan.
• The onslaught of WD start in December and
continue up to March
• Balochistan receives large share of rainfall i.e 150 to
250 mm annually.
• Owing to WD rivers of Balochistan swell in winter.

24. CONVECTION OF EARTH

25. Types of Rainfall in Pakistan
• Convectional rainfall
• Very common in areas where the ground is heated by the hot sun, such as the Tropics. This is why
those areas experience heavy rainfalls most afternoons. The United Kingdom does experience some
convectional rainfall during the summer, particularly in the South East of the country.
•
• Convectional rainfall occurs when:
• The surface of the earth is heated by the sun.
• The warm surface heats the air above it. Hot air always rises so this newly heated air does so.
• As it rises the air-cools and begins to condensate.
• Further rising and cooling causes a large amount of condensation to occur and rain is formed.
• Convection tends to produce towering cumulus-nimbus clouds, which produce heavy rain and
possible thunder and lightning.
• Convectional rainfall in Pakistan (April to June and October to November)
• The convectional rainfall brings thunderstorm and sporadic and localized rainfall in Pakistan
• This type of rainfall happens on the foothills and plateaus.
• The amount of rainfall is more than 50 mm on mountains

26. RAINFALL IN PAKISTAN

28. PAKISTAN - MINIMUM TEMPERATURE

29. Types of Rainfall in Pakistan
• Relief rainfall
• This is also called aerographic rainfall, which is very common in the United
Kingdom, especially on the West coast since the prevailing weather comes from
that direction.
• Relief Rainfall occurs when:
• The prevailing winds pick up moisture from the sea as they travel across it, making
the air moist.
• The moist air reaches the coast and is forced to rise over mountains and hills.
• This forces the air to cool and condense, forming clouds.
• The air continues to be forced over the mountains and so it drops its moisture as
relief rain.
• Once over the top of the mountain the air will usually drop down the other side,
warming as it does so. This means it has a greater ability to carry water moisture
and so there is little rain on the far side of the mountain. This area is called
the rain shadow.
• Relief rainfall in Pakistan
• The relief rainfall happens in Pakistan along the coastal areas and foothills

30. TEMPERATURE - ISLAMABAD

31. SEA BREEZE

33. ISLAMABAD- TEMPERATURE & RAINFALL

36. RAINFALL IN PAKISTAN

38. Tropical Cyclones
• Tropical storms
• Otherwise known as hurricanes, cyclones, typhoons, and wily willies (the
Australian name!). These are very intense areas of very low pressure,
approximately 500 to 1000 kilometers in diameter.
• Tropical storms form over water that is above 26.5°C in temperature. The
warm water heats the air above it, causing it to rise rapidly. Cooler air from
elsewhere rapidly moves in to replace the rising air and the process starts
again.
• The rapidly rising moist air, cools as it ascends and forms tall cumulo-nimbus
clouds. These slowly spin around the central point. Jet streams above the
storm clouds continue to suck the air up.
• Cooling air sinks down through the spiraling mass of clouds to produce a
central eye of the storm.
• Tropical storms move quickly over water, as long as it is warms enough to
keep the storm energized. Once over land, where there is less moisture and
the surface is cooler, tropical storms quickly calm down.
• The main effects of a tropical storm are the very strong winds, torrential rain
and storm surges. These all can cause massive damage and huge loss of life.

39. Tropical Cyclones
• The sequence of events as a tropical storm travelled overhead would be:
• As the storm approached there would be a drop in temperature and pressure. Wind
speeds would begin to increase and clouds would form.
• As the storm is overhead the pressure would fall rapidly, as would the temperature.
Wind speeds would be in excess of 150km/hr and the rain would be torrential. The
wind would whip up waves that could swamp entire coastal areas, or drown entire coral
islands in the Pacific.
• The eye of the storm is overhead. Skies are clear, the temperature and pressure
increase, and the wind dies down. Unfortunately this is only a brief lull in the storm.
• The storm hits again. Temperature and pressure falls. Torrential rain and wind speeds of
over 100km/hr occur. The winds are now coming form the opposite direction than they
were before.
• After the storm the temperature and pressure rise again. The rain becomes showers,
and the winds die down. The clean up operation begins!
• Example: Hurricane Floyd, September 1999
• Hit the coast of Florida and then moved north towards Georgia and South Carolina.
• Torrential rain and 155mph winds battered the area, bringing down power and phone
lines and snapping trees.
• It whipped up 20-foot waves along the coast.