September Weather in Chengdong ChinaDaily high temperatures decrease by 6°F, from 91°F to 86°F, rarely falling below 78°F or exceeding 97°F. Daily low temperatures decrease by 6°F, from 75°F to 69°F, rarely falling below 63°F or exceeding 79°F. For reference, on July 17, the hottest day of the year, temperatures in Chengdong typically range from 77°F to 94°F, while on January 23, the coldest day of the year, they range from 45°F to 62°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. Houston, United States (8,018 miles away); St. Marys, United States (8,345 miles); and Bou Attouche, Tunisia (6,242 miles) are the far-away foreign places with temperatures most similar to Chengdong (view comparison). CloudsThe month of September in Chengdong experiences very rapidly decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 64% to 42%. The clearest day of the month is September 30, with clear, mostly clear, or partly cloudy conditions 58% of the time. For reference, on June 25, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 80%, while on December 26, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 79%. PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Chengdong, the chance of a wet day over the course of September is very rapidly decreasing, starting the month at 34% and ending it at 17%. For reference, the year's highest daily chance of a wet day is 47% on May 30, and its lowest chance is 8% on October 24. RainfallTo show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day. The average sliding 31-day rainfall during September in Chengdong is very rapidly decreasing, starting the month at 5.3 inches, when it rarely exceeds 9.7 inches or falls below 1.5 inches, and ending the month at 2.7 inches, when it rarely exceeds 5.9 inches or falls below 0.4 inches. SunOver the course of September in Chengdong, the length of the day is decreasing. From the start to the end of the month, the length of the day decreases by 42 minutes, implying an average daily decrease of 1 minute, 28 seconds, and weekly decrease of 10 minutes, 14 seconds. The shortest day of the month is September 30, with 11 hours, 56 minutes of daylight and the longest day is September 1, with 12 hours, 38 minutes of daylight. The earliest sunrise of the month in Chengdong is 5:45 AM on September 1 and the latest sunrise is 11 minutes later at 5:56 AM on September 30. The latest sunset is 6:24 PM on September 1 and the earliest sunset is 31 minutes earlier at 5:52 PM on September 30. Daylight saving time is not observed in Chengdong during 2024. For reference, on June 20, the longest day of the year, the Sun rises at 5:15 AM and sets 13 hours, 43 minutes later, at 6:58 PM, while on December 21, the shortest day of the year, it rises at 6:46 AM and sets 10 hours, 34 minutes later, at 5:20 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 Chengdong is very rapidly decreasing during September, falling from 95% to 53% over the course of the month. For reference, on July 22, the muggiest day of the year, there are muggy conditions 100% of the time, while on January 21, 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 Chengdong is increasing during September, increasing from 7.0 miles per hour to 8.8 miles per hour over the course of the month. For reference, on October 19, the windiest day of the year, the daily average wind speed is 9.4 miles per hour, while on August 23, the calmest day of the year, the daily average wind speed is 6.6 miles per hour. The hourly average wind direction in Chengdong throughout September is predominantly from the north, with a peak proportion of 57% on September 30. Water TemperatureChengdong 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 Chengdong is gradually decreasing during September, falling by 3°F, from 81°F to 78°F, over the course of the month. 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). While it does not do so every year, freezing temperatures are seen in Chengdong over some winters. The day least likely to be in the growing season is January 14, with a 59% chance. 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 Chengdong are rapidly increasing during September, increasing by 821°F, from 4,723°F to 5,544°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 Chengdong is essentially constant during September, remaining within 0.1 kWh of 5.3 kWh throughout. TopographyFor the purposes of this report, the geographical coordinates of Chengdong are 25.368 deg latitude, 118.701 deg longitude, and 171 ft elevation. The topography within 2 miles of Chengdong contains very significant variations in elevation, with a maximum elevation change of 1,227 feet and an average elevation above sea level of 245 feet. Within 10 miles contains very significant variations in elevation (2,881 feet). Within 50 miles contains large variations in elevation (6,030 feet). The area within 2 miles of Chengdong is covered by cropland (42%), artificial surfaces (32%), and trees (10%), within 10 miles by trees (48%) and cropland (22%), and within 50 miles by trees (47%) and water (20%). Data SourcesThis report illustrates the typical weather in Chengdong, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016. Temperature and Dew PointThere are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Chengdong. For each station, the records are corrected for the elevation difference between that station and Chengdong according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations. The estimated value at Chengdong is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Chengdong and a given station. The stations contributing to this reconstruction are:
To get a sense of how much these sources agree with each other, you can view a comparison of Chengdong and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data. Other DataAll 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. 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. We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader. Please review our full terms contained on our Terms of Service page. |