Average Weather in December in Jiayi China
Daily high temperatures decrease by 6°F, from 71°F to 66°F, rarely falling below 54°F or exceeding 80°F.
Daily low temperatures decrease by 6°F, from 51°F to 45°F, rarely falling below 34°F or exceeding 60°F.
For reference, on July 24, the hottest day of the year, temperatures in Jiayi typically range from 74°F to 87°F, while on January 12, the coldest day of the year, they range from 45°F to 64°F.
Average High and Low Temperature in December
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on December. 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.
Average Hourly Temperature in December
The month of December in Jiayi experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 27% throughout the month. The lowest chance of overcast or mostly cloudy conditions is 26% on December 13.
The clearest day of the month is December 13, with clear, mostly clear, or partly cloudy conditions 74% of the time.
For reference, on June 21, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 85%, while on December 13, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 74%.
Cloud Cover Categories in December
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Jiayi, the chance of a wet day over the course of December is essentially constant, remaining around 10% throughout.
For reference, the year's highest daily chance of a wet day is 61% on June 2, and its lowest chance is 8% on December 19.
Probability of Precipitation in December
To 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 December in Jiayi is essentially constant, remaining about 1.1 inches throughout, and rarely exceeding 3.6 inches or falling below -0.0 inches.
The lowest average 31-day accumulation is 1.0 inches on December 17.
Average Monthly Rainfall in December
Over the course of December in Jiayi, the length of the day is essentially constant. The shortest day of the month is December 22, with 10 hours, 45 minutes of daylight and the longest day is December 1, with 10 hours, 51 minutes of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Jiayi is 6:58 AM on December 1 and the latest sunrise is 17 minutes later at 7:15 AM on December 31.
The earliest sunset is 5:49 PM on December 1 and the latest sunset is 11 minutes later at 6:01 PM on December 31.
Daylight saving time is not observed in Jiayi during 2018.
For reference, on June 21, the longest day of the year, the Sun rises at 5:51 AM and sets 13 hours, 32 minutes later, at 7:23 PM, while on December 21, the shortest day of the year, it rises at 7:10 AM and sets 10 hours, 45 minutes later, at 5:55 PM.
Sunrise & Sunset with Twilight in December
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 Jiayi is decreasing during December, falling from 6% to 1% over the course of the month.
For reference, on June 30, the muggiest day of the year, there are muggy conditions 100% of the time, while on January 8, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in December
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 Jiayi is essentially constant during December, remaining within 0.1 miles per hour of 7.6 miles per hour throughout.
For reference, on March 28, the windiest day of the year, the daily average wind speed is 8.8 miles per hour, while on August 20, the calmest day of the year, the daily average wind speed is 6.0 miles per hour.
The highest daily average wind speed during December is 7.7 miles per hour on December 1.
Average Wind Speed in December
Wind Direction in December
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).
While it does not do so every year, freezing temperatures are seen in Jiayi over some winters. The day least likely to be in the growing season is January 10, with a 61% chance.
Time Spent in Various Temperature Bands and the Growing Season in December
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 Jiayi are increasing during December, increasing by 245°F, from 6,948°F to 7,193°F, over the course of the month.
Growing Degree Days in December
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 Jiayi is essentially constant during December, remaining within 0.1 kWh of 4.1 kWh throughout.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Jiayi are 22.707 deg latitude, 111.150 deg longitude, and 1,125 ft elevation.
The topography within 2 miles of Jiayi contains very significant variations in elevation, with a maximum elevation change of 1,362 feet and an average elevation above sea level of 1,141 feet. Within 10 miles contains very significant variations in elevation (3,711 feet). Within 50 miles also contains extreme variations in elevation (5,541 feet).
The area within 2 miles of Jiayi is covered by trees (82%) and shrubs (11%), within 10 miles by trees (84%), and within 50 miles by trees (71%) and shrubs (12%).
This report illustrates the typical weather in Jiayi year round, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There is only a single weather station, Zhanjiang Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Jiayi.
At a distance of 183 kilometers from Jiayi, further than our threshold of 150 kilometers, this station is deemed insufficiently nearby to be relied upon as our primary source for temperature and dew point records. Consequently, the station records are blended with interpolated values from NASA's MERRA-2 satellite-era reanalysis , and both are corrected for elevation differences according to the International Standard Atmosphere .
The weight assigned to the MERRA-2 value depends on the distance from Jiayi to the nearest station, increasing from 0% at 150 kilometers to 100% at 200 kilometers. In this case, the MERRA-2 weight is 40%, making the weight assigned to the weather station 60%.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , 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 aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The 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.