Historical Weather For 2012 in Islamabad, Pakistan

Location

This report describes the historical weather record at the Benazir Bhutto International Airport/PAF Base Chaklala (Islamabad, Pakistan) during 2012. This station has records back to January 1948.

Islamabad has a warm temperate climate with dry winters and hot summers. The area within 25 mi of this station is covered by croplands (73%), shrublands (23%), and built-up areas (3%)

Calendar

Daylight saving time (DST) was not observed at Islamabad during 2012.

2012 was a leap year and thus has 366 days rather than the normal 365. Leap years occur every fourth year and the extra day is always February 29th. In 2012 February 29th falls on a Wednesday.

The summer and winter solstices and the spring and fall equinoxes mark the passing of the seasons. They fall on nearly the same day each year, with differences of a day or two depending on the year. In 2012 they occurred on:

Spring Equinox Tuesday, 20 March 2012.
Summer Solstice Wednesday, 20 June 2012.
Fall Equinox Saturday, 22 September 2012.
Winter Solstice Friday, 21 December 2012.

Temperature

The hottest day of 2012 was June 22, with a high temperature of 113°F. For reference, on that day the average high temperature is 99°F and the high temperature exceeds 107°F only one day in ten. The hottest month of 2012 was June with an average daily high temperature of 105°F.

Relative to the average, the hottest day was July 2. The high temperature that day was 113°F, compared to the average of 98°F, a difference of 15°F. In relative terms the warmest month was July, with an average high temperature of 101°F, compared to an typical value of 95°F.

The longest warm spell was from June 19 to July 7, constituting 19 consecutive days with warmer than average high temperatures. The month of June had the largest fraction of warmer than average days with 87% days with higher than average high temperatures.

Temperature

The daily low (blue) and high (red) temperature during 2012 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile). The bar at the top of the graph is red where both the daily high and low are above average, blue where they are both below average, and white otherwise.

The coldest day of 2012 was January 8, with a low temperature of 33°F. For reference, on that day the average low temperature is 40°F and the low temperature drops below 35°F only one day in ten. The coldest month of 2012 was January with an average daily low temperature of 40°F.

Relative to the average, the coldest day was February 15. The low temperature that day was 36°F, compared to the average of 46°F, a difference of 10°F. In relative terms the coldest month was February, with an average low temperature of 43°F, compared to an typical value of 46°F.

The longest cold spell was from January 7 to January 15, constituting 9 consecutive days with cooler than average low temperatures. The month of February had the largest fraction of cooler than average days with 66% days with lower than average low temperatures.

Hourly Temperature Bands

The full year of hourly temperature reports with the days of the year on the horizontal and the hours of the day on the vertical. The hourly temperature measurement is color coded into meaningful temperature bands: frigid is purple (below 15°F), freezing is blue (15°F to 32°F), cold is dark green (32°F to 50°F), cool is light green (50°F to 65°F), comfortable is yellow (65°F to 75°F), warm is light red (75°F to 85°F), hot is medium red (85°F to 100°F), sweltering is dark red (above 100°F), and missing data is pink.

Clouds

The clearest month of 2012 was October, with 84% of days being more clear than cloudy. The longest spell of clear weather was from September 18 to October 14, constituting 27 consecutive days that were clearer than they were cloudy.

Cloud Coverage

The fraction of time spent in each of the five sky cover categories over the course of 2012 on a daily basis. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data. The bar at the top of the graph is gray if the sky was cloudy or mostly cloudy for more than half the day, blue if it is clear or mostly clear for more than half the day, and blue-gray otherwise.

The cloudiest month of 2012 was February, with 31% of days being more cloudy than clear. The longest spell of cloudy weather was from February 1 to February 5, constituting 5 consecutive days that were cloudier than they were clear.

Hourly Cloud Coverage

The full year of hourly cloud coverage reports with the days of the year on the horizontal and the hours of the day on the vertical. The sky cover is color coded: from most blue to most gray, the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.

Precipitation

This station provides hourly reports of significant weather events at and around the station, but does not report the quantity of precipitation at the station itself. This is common for weather stations located outside of the United States, and for a small subset of stations in the United States that are located at lesser used and smaller airports.

Present Weather Reports

This station reports when significant weather events (including precipitation) are visually observed at or near the station. Such events do not always correspond to measured quantities of liquid equivalent precipitation, such as when the event is near by not at the station, or in the case of solid precipitation that does not melt in the collection basin.

The day in 2012 with the most precipitation observations was January 15. There were 21 hourly weather reports that day (out of a maximum of 24) in which some form of precipitation was observated at or near the station. The month with the most precipitation observations was August, with 126 hourly present weather reports involving some form of precipitation.

Precipitation Reports

The daily number of hourly observed precipitation reports during 2012, color coded according to precipitation type, and stacked in order of severity. From the bottom up, the categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); and drizzle (lightest green). Not all categories are necessarily present in this particular graph. The faint shaded areas indicate climate normals. The bar at the top of the graph is green if any precipitation was observed that day and white otherwise.

As determined by the present weather reports, the longest dry spell was from November 6 to November 28, constituting 23 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was November, with 90% of days reporting no observed precipitation at all.

The month with the largest fraction of days with at least some observed precipitation was April, with 70% of days reporting some observed precipitation.

Hourly Weather Reports

The full year of hourly present weather reports with the days of the year on the horizontal and the hours of the day on the vertical. The color-coded categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); drizzle (lightest green); freezing rain and sleet (light and dark cyan); snow grains (lightest blue); hail (red); fog (gray); and haze (brownish gray).

Snow

Either snow is exceptionally rare at this location or this station did not reliably report it during 2012.

Humidity

Humidity is an important factor in determining how weather conditions feel to a person experiencing them. Hot and humid days feel even hotter than hot and dry days because the high level of water content in humid air discourages the evaporation of sweat from a person's skin.

When reading the graph below, keep in mind that the hottest part of the day tends to be the least humid, so the daily low (brown) traces are more relevant for understanding daytime comfort than the daily high (blue) traces, which typically occur during the night. Applying that observation, the least humid month of 2012 was June with an average daily low humidity of 19%, and the most humid month was August with an average daily low humidity of 56%.

But it is important to keep in mind that humidity does not tell the whole picture and the dew point is often a better measure of how comfortable a person will find a given set of weather conditions. Please see the next section for continued discussion of this point.

Humidity

The daily low (brown) and high (blue) relative humidity during 2012 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Dew Point

Dew point is the temperature below which water vapor will condense into liquid water. It is therefore also related to the rate of evaporation of liquid water. Since the evaporation of sweat is an important cooling mechanism for the human body, the dew point is an important measurement for understanding how dry, comfortable, or humid a given set of weather conditions will feel.

Generally speaking, dew points below 50°F will feel a bit dry to some people, but comfortable to people accustomed to dry conditions; dew points from 50°F to 68°F are fairly comfortable to most people, and dew points above 68°F are increasingly uncomfortable, becoming oppressive around 77°F.

To take some examples, and basing our categorization on the daily high dew point in 2012, January had 30 dry days, 1 comfortable day, and no humid days; April had no dry days, 30 comfortable days, and no humid days; July had no dry days, 1 comfortable day, and 30 humid days; and October had no dry days, 31 comfortable days, and no humid days.

Dew Point

The daily low (blue) and high (red) dew point during 2012 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Wind

The highest sustained wind speed was 75 mph, occurring on February 24; the highest daily mean wind speed was 25 mph (May 25);

The windiest month was July, with an average wind speed of 12 mph. The least windy month was November, with an average wind speed of 4 mph.

Wind Speed

The daily low and high wind speed (light gray area) and the maximum daily wind gust speed (tiny blue dashes).

Visibility

Visibility is the maximum distance at which a given reference object or light can be clearly discerned. In the United States, visibilities that are greater than or equal to 10 miles are typically reported as 10 miles.

The day of 2012 with the lowest average visibility was March 20, with an average visibility of 0.8 mi. The month with the lowest average visibility was December, with an average visibility of 2.1 mi. With an average visibility of 3.8 mi, the month of May had the highest average visibility.

Visibility

The daily average visibility, depicted as gray bars encroaching down from the top of the graph.

Cloud Ceiling

The cloud ceiling is the altitude of the lowest layer of clouds that are at categorized as broken (mostly cloudy) or overcast (cloudy). If no such cloud layer exists then the ceiling is unlimited and no value is reported.

The day of 2012 with the lowest average cloud ceiling was March 21, with an average cloud ceiling of 49'. The month with the lowest average cloud ceiling was October, with an average cloud ceiling of 9269'. The month of March has the highest average cloud ceiling, with an average cloud ceiling of 10460'.

Cloud Ceiling

The daily average cloud ceiling, depicted as gray bars encroaching down from the top of the graph. Missing data or days with insufficient clouds to define a cloud ceiling are shown as white columns.