September Weather in Şanā’ YemenDaily high temperatures decrease by 5°F, from 100°F to 94°F, rarely falling below 92°F or exceeding 102°F. Daily low temperatures decrease by 7°F, from 74°F to 67°F, rarely falling below 64°F or exceeding 77°F. For reference, on July 3, the hottest day of the year, temperatures in Şanā’ typically range from 76°F to 101°F, while on January 3, the coldest day of the year, they range from 51°F to 81°F. The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on September. 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. El Fuerte de Montes Claros, Mexico (9,151 miles away) is the far-away foreign place with temperatures most similar to Şanā’ (view comparison). CloudsThe month of September in Şanā’ experiences rapidly decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 39% to 25%. The clearest day of the month is September 30, with clear, mostly clear, or partly cloudy conditions 75% of the time. For reference, on June 8, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 67%, while on November 26, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 83%. PrecipitationSunOver the course of September in Şanā’, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 25 minutes, implying an average daily decrease of 51 seconds, and weekly decrease of 5 minutes, 57 seconds. The shortest day of the month is September 30, with 12 hours, 0 minutes of daylight and the longest day is September 1, with 12 hours, 25 minutes of daylight. The earliest sunrise of the month in Şanā’ is 5:36 AM on September 1 and the latest sunrise is 2 minutes, 17 seconds later at 5:38 AM on September 30. The latest sunset is 6:01 PM on September 1 and the earliest sunset is 22 minutes earlier at 5:38 PM on September 30. Daylight saving time is not observed in Şanā’ during 2024. For reference, on June 20, the longest day of the year, the Sun rises at 5:19 AM and sets 13 hours, 3 minutes later, at 6:21 PM, while on December 21, the shortest day of the year, it rises at 6:10 AM and sets 11 hours, 13 minutes later, at 5:23 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. MoonThe figure below presents a compact representation of key lunar data for September 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.
HumidityWe 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 Şanā’ is essentially constant during September, remaining within 1% of 1% throughout. For reference, on August 5, the muggiest day of the year, there are muggy conditions 3% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time. WindThis 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 Şanā’ is gradually decreasing during September, decreasing from 7.6 miles per hour to 7.0 miles per hour over the course of the month. For reference, on August 1, the windiest day of the year, the daily average wind speed is 9.8 miles per hour, while on December 22, the calmest day of the year, the daily average wind speed is 6.7 miles per hour. The lowest daily average wind speed during September is 6.9 miles per hour on September 21. The wind direction in Şanā’ during September is predominantly out of the south from September 1 to September 17 and the east from September 17 to September 30. Growing SeasonDefinitions 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 Şanā’ 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 Şanā’ are rapidly increasing during September, increasing by 889°F, from 6,527°F to 7,416°F, over the course of the month. Solar EnergyThis 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 Şanā’ is essentially constant during September, remaining within 0.1 kWh of 7.2 kWh throughout. The highest average daily incident shortwave solar energy during September is 7.2 kWh on September 20. TopographyFor the purposes of this report, the geographical coordinates of Şanā’ are 15.400 deg latitude, 47.767 deg longitude, and 2,940 ft elevation. The topography within 2 miles of Şanā’ contains very significant variations in elevation, with a maximum elevation change of 1,490 feet and an average elevation above sea level of 3,379 feet. Within 10 miles contains very significant variations in elevation (2,054 feet). Within 50 miles contains large variations in elevation (3,602 feet). The area within 2 miles of Şanā’ is covered by bare soil (42%), water (33%), and sparse vegetation (24%), within 10 miles by bare soil (57%) and sparse vegetation (33%), and within 50 miles by bare soil (69%) and sparse vegetation (23%). Data SourcesThis report illustrates the typical weather in Şanā’, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016. Şanā’ is further than 200 kilometers from the nearest reliable weather station, so the weather-related data on this page were taken entirely from NASA's MERRA-2 satellite-era reanalysis . 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. The temperature and dew point estimates are corrected for the difference between the reference elevation of the MERRA-2 grid cell and the elevation of Şanā’, according to the International Standard Atmosphere . 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. 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. DisclaimerThe information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site. We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands. 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