Climate of Islamabad – The Monthly factors!

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Islamabad has a typical version of a humid subtropical climate, with hot summers accompanied by a monsoon season followed by fairly cold winters. The hottest months are May and June, where average highs routinely exceed 38 °C (100.4 °F). The monsoon season is from June to September, with heavy rainfalls and evening thunderstorms with the possibility of cloudburst. Winters are lasted from November to March with temperatures variable by location. In the city, temperatures vary from cold to mild, routinely dropping below zero. In the hills there is sparse snowfall. The weather ranges from a minimum of 3.9 °C (39.0 °F) in January to a maximum of 46.1 °C (115.0 °F) in June. The average low is 2 °C (35.6 °F) in January, while the average high is 40 °C (104.0 °F) in June. The highest temperature recorded was 48 °C (118.4 °F) in June, while the lowest temperature was −4 °C (24.8 °F) in January. On 23 July 2001, Islamabad received a record breaking 620 millimetres (24 in) of rain fell in just 10 hours. It was the heaviest rainfall in 24 hours in Islamabad and at any locality in Pakistan during the past 100 years.

 Factors

The monsoon and the Western Disturbance are the two main factors that change the weather over Islamabad; otherwise, Continental air prevails for rest of the seasons. Following are the main factors that influence the weather over Islamabad.

• Western Disturbances occur almost every month in the city, but peaking during the winter months and causes moderate to heavy rainfall, temperature also decreases due to it. These westerly waves are robbed of most of the moisture by the time they reach Islamabad.
• Fog do occur during the winter season and remains for weeks; especially near Margalla Hills.
• Dust storm occur during summer months with peak in May and June. These dust storm are quite violent.
• Southwest Monsoon occurs in summer from the month of June till September. These monsoon rains are quite heavy by nature and can cause severe flooding if they interact with westerly waves.
• Continental air prevails during the period when there is no precipitation in the city.

Monthly weather conditions

The following is the monthly summary of the climatic conditions in Islamabad.

January

January is the coldest month of Islamabad. In January the weather of Islamabad is mild. Rains in this month is heavy like in other season of the city. Typical to Islamabad, there is no snow experienced in the region. Western Disturbance has a great influence in the winter of the city. it produces rains and sometimes hailstorms. The highest temperature is 30.1 °C (86.2 °F) (1995) and lowest temperature is −3.9 °C (25 °F) (1967). While the heaviest rainfall for this month is 166.7 millimetres (6.56 in) (1954).

February

The weather of Islamabad in February is similar to that of January. The weather remains mild. Western Disturbance cause rains just like in January. The highest temperature ever recorded was 30 °C (86 °F) (1985) and lowest temperature is −2 °C (28.4 °F). While the highest rainfall is 268.5 millimetres (10.57 in) (1998).

March

In the month of March the weather starts to settle, In march the weather turns little hot making the weather pleasant. Humidity in this month is about 37%. Again Western Disturbance has a effect on the weather, producing rain and hail. It causes rains with strong winds. Western Disturbance has no timing, it effects the upper and northern parts of Pakistan including Islamabad in every month and season. In this scenario Islamabad gets heavy showers and rains in every month including March. The highest temperature is 34.4 °C (93.9 °F) and the lowest is 0 °C (32 °F). The highest rainfall for march is 224.1 millimetres (8.82 in) (1984).

April

The weather pattern of Islamabad in April is identical to that of March. The weather gets hot in this month, the highest temperature recorded was 40.6 °C (105.1 °F) (2006) and lowest temperature is 5 °C (41 °F) (1994). Humidity remains low in this month about 24%. While the highest rainfall is 264.5 millimetres (10.41 in) (1983).

May

In May the weather gets very hot in the city. The highest temperature is 45 °C (113 °F) (1988) and lowest is 10.0 °C (50.0 °F) (1997). Humidity gets extremely low in May as compared to other month, which is of 19%. Evening thunderstorms can occur in this month accompanied by dust storms that give the citizens of Islamabad much awaited relief from the scorching heat. The highest rainfall is 115.6 millimetres (4.55 in) (1965)

June

June is the hottest month of Islamabad. Temperatures in this month reach till 48 °C (118 °F) as recorded in 2005, While the lowest temperature is 15.7 °C (60.3 °F) (1979). Till the first week of June the weather is identical to May. But in the middle of June Pre-Monsoon showers can start that come from South west Monsoon. Again Western Disturbance too can cause heavy showers, which is not a part of monsoon. Dust storms are common in this month which are locally called as Andhi. The highest rainfall for the month of June is 255 millimetres (10.0 in) (2008). On June 23, 2010, a massive dust storm of 81 mph (130 km/h) hit the city followed by drizzle before the storm, temperatures peaked above 40 °C (104 °F) for four consecutive days.

July

July is the Annual Monsoon season and the wettest month for Islamabad as well as for whole Pakistan that continues till September. In July Islamabad can see some very heavy falls of rain accompanied by Strong Thunderstorms and windstorms. These heavy storms is due to the moisture coming from Arabian Sea and Bay of Bengal and sometimes if western disturbance interact with them then record rain can be seen. Humidity remains above 65%. The highest temperature in this month is 44.4 °C (111.9 °F) (1987) and lowest temperature is 17 °C (63 °F) (1966) and the highest rainfall for this month is 743.5 millimetres (29.27 in) (1995). The heaviest rain of the city was also recorded in this month when 620 millimetres (24 in) rain occurred in just 10 hours on July 23, 2001 the continuous downpour lasted from 0600 to 1600 PST. In July 2008, a severe rainfall spell, that lasted from 4 to 9 July, produced a heavy rainfall of 162 millimetres (6.4 in) in 5 hours. It was the heaviest short period rainfall in last six years reminding the cloud burst of July 23, 2001.

August

Monsoon rains continue in August as well. The month of August is the most humid month for Islamabad. The highest temperature is 42 °C (108 °F) (1987) and the lowest temperature is 17 °C (63 °F) (1976). While the highest rainfall for this month is 645.5 millimetres (25.41 in) (1982).

September

Monsoon rains continue till the Mid-week of September, after that monsoon completely withdraws from the city. Western disturbance cause showers or little drizzle in this month. The highest temperature is 38.1 °C (100.6 °F) (1982) and lowest is 13 °C (55 °F) (1994). The highest rains in this month is 279.1 millimetres (10.99 in) (1961).

October

 October is the driest month in the city. There is drizzle in this month due to westerly wave. The highest rainfall for this month is 95 millimetres (3.7 in) (1997). The highest temperature and lowest temperature is 36 °C (97 °F) (1998)and 5 °C (41 °F) (1984) respectively.

November

The first to second weeks of November is identical to October. But after that Cold winds start to enter the city. Some days of November are hot while other cold. Showers or hailstorms occur in this month too. The highest rainfall for this month is 91 millimetres (3.6 in) (1959) and the highest and lowest temperature is 32 °C (90 °F) (1999) and 0 °C (32 °F) (1970) respectively.

December

In the month is December the winter finally sets in, while the coldest winter of the city is observed in January, weather becomes quite chilly in December too. Western Disturbance cause rain in this month. The highest rainfall for this month is 177.9 millimetres (7.00 in) (1990). The lowest temperature and highest temperature is −2.8 °C (27 °F) (1984) and 28 °C (82 °F) (1998) respectively.