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:News/Updates
Daily high temperatures increase by 9°F, from 85°F to 94°F, rarely falling below 79°F or exceeding 100°F. Daily low temperatures increase by 19°F, from 64°F to 83°F, rarely falling below 58°F or exceeding 85°F. For reference, on June 6, the hottest day of the year, temperatures in Karachi typically range from 84°F to 94°F, while on January 6, the coldest day of the year, they range from 55°F to 78°F.
The figure below shows you a compact characterization of the hourly average spring temperatures. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
The spring in Karachi experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 18% to 23%. The clearest day of the spring is May 15, with clear, mostly clear, or partly cloudy conditions 85% of the time. For reference, on July 29, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 57%, while on October 25, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 94%.
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Karachi, the chance of a wet day over the course of the spring is essentially constant, remaining around 1% throughout. For reference, the year's highest daily chance of a wet day is 14% on July 29, and its lowest chance is 0% on May 17.
To show variation within the season and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day. The average sliding 31-day rainfall during the spring in Karachi is essentially constant, remaining about 0.1 inches throughout, and rarely exceeding 0.6 inches or falling below -0.0 inches. The lowest average 31-day accumulation is 0.0 inches on May 4.
Over the course of the spring in Karachi, the length of the day is rapidly increasing. From the start to the end of the season, the length of the day increases by 1 hour, 55 minutes, implying an average daily increase of 1 minute, 16 seconds, and weekly increase of 8 minutes, 50 seconds. The shortest day of the spring is March 1, with 11 hours, 40 minutes of daylight and the longest day is May 31, with 13 hours, 35 minutes of daylight.
The latest sunrise of the spring in Karachi is 6:54 AM on March 1 and the earliest sunrise is 1 hour, 12 minutes earlier at 5:42 AM on May 31. The earliest sunset is 6:34 PM on March 1 and the latest sunset is 43 minutes later at 7:16 PM on May 31. Daylight saving time is not observed in Karachi during 2024. For reference, on June 20, the longest day of the year, the Sun rises at 5:42 AM and sets 13 hours, 41 minutes later, at 7:23 PM, while on December 21, the shortest day of the year, it rises at 7:12 AM and sets 10 hours, 35 minutes later, at 5:47 PM.
The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.
The figure below presents a compact representation of key lunar data for the spring of 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night. The chance that a given day will be muggy in Karachi is very rapidly increasing during the spring, rising from 16% to 97% over the course of the season. For reference, on July 5, the muggiest day of the year, there are muggy conditions 100% of the time, while on January 18, the least muggy day of the year, there are muggy conditions 2% of the time.
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages. The average hourly wind speed in Karachi is very rapidly increasing during the spring, increasing from 8.8 miles per hour to 14.3 miles per hour over the course of the season. For reference, on June 29, the windiest day of the year, the daily average wind speed is 14.7 miles per hour, while on November 26, the calmest day of the year, the daily average wind speed is 6.9 miles per hour.
The hourly average wind direction in Karachi throughout the spring is predominantly from the west, with a peak proportion of 92% on May 1.
Karachi is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water. The average surface water temperature in Karachi is rapidly increasing during the spring, rising by 10°F, from 74°F to 84°F, over the course of the season.
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere). Temperatures in Karachi are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F. The average accumulated growing degree days in Karachi are very rapidly increasing during the spring, increasing by 2,826°F, from 1,127°F to 3,953°F, over the course of the season.
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation. The average daily incident shortwave solar energy in Karachi is increasing during the spring, rising by 1.4 kWh, from 6.0 kWh to 7.3 kWh, over the course of the season. The highest average daily incident shortwave solar energy during the spring is 7.4 kWh on May 23.
For the purposes of this report, the geographical coordinates of Karachi are 24.906 deg latitude, 67.082 deg longitude, and 125 ft elevation. The topography within 2 miles of Karachi contains only modest variations in elevation, with a maximum elevation change of 177 feet and an average elevation above sea level of 122 feet. Within 10 miles contains only modest variations in elevation (604 feet). Within 50 miles contains significant variations in elevation (3,547 feet). The area within 2 miles of Karachi is covered by artificial surfaces (100%), within 10 miles by artificial surfaces (76%) and bare soil (14%), and within 50 miles by bare soil (45%) and water (39%).
This report illustrates the typical weather in Karachi, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
There is only a single weather station, Karachi Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Karachi. At a distance of 8 kilometers from Karachi, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records. The station records are corrected for the elevation difference between the station and Karachi according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations. Please note that the station records themselves may additionally have been back-filled using other nearby stations or the MERRA-2 reanalysis.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus. All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid. Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations. Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory. Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database . Time zones for airports and weather stations are provided by AskGeo.com . Maps are © OpenStreetMap contributors.