Climate and Average Weather Year Round in Sishan China

In Sishan, the summers are warm, oppressive, wet, and overcast and the winters are very cold, snowy, and partly cloudy. Over the course of the year, the temperature typically varies from 28°F to 84°F and is rarely below 18°F or above 90°F.

Based on the tourism score, the best time of year to visit Sishan for warm-weather activities is from mid July to late September.

The warm season lasts for 3.2 months, from June 11 to September 17, with an average daily high temperature above 77°F. The hottest month of the year in Sishan is July, with an average high of 84°F and low of 65°F.

The cold season lasts for 3.1 months, from December 2 to March 5, with an average daily high temperature below 53°F. The coldest month of the year in Sishan is January, with an average low of 28°F and high of 46°F.

In Sishan, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Sishan begins around September 9 and lasts for 6.2 months, ending around March 16.

The clearest month of the year in Sishan is December, during which on average the sky is clear, mostly clear, or partly cloudy 69% of the time.

The cloudier part of the year begins around March 16 and lasts for 5.8 months, ending around September 9.

The cloudiest month of the year in Sishan is June, during which on average the sky is overcast or mostly cloudy 76% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Sishan varies significantly throughout the year.

The wetter season lasts 6.7 months, from February 17 to September 9, with a greater than 34% chance of a given day being a wet day. The month with the most wet days in Sishan is June, with an average of 15.5 days with at least 0.04 inches of precipitation.

The drier season lasts 5.3 months, from September 9 to February 17. The month with the fewest wet days in Sishan is December, with an average of 4.5 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Sishan is June, with an average of 15.5 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 55% on June 9.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Sishan experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in Sishan. The month with the most rain in Sishan is June, with an average rainfall of 10.8 inches.

The month with the least rain in Sishan is December, with an average rainfall of 1.3 inches.

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Sishan experiences significant seasonal variation in monthly snowfall.

The snowy period of the year lasts for 4.2 months, from November 26 to April 2, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Sishan is February, with an average snowfall of 8.0 inches.

The snowless period of the year lasts for 7.8 months, from April 2 to November 26. The least snow falls around July 30, with an average total accumulation of 0.0 inches.

The length of the day in Sishan varies over the course of the year. In 2024, the shortest day is December 21, with 10 hours, 23 minutes of daylight; the longest day is June 21, with 13 hours, 54 minutes of daylight.

The earliest sunrise is at 5:07 AM on June 9, and the latest sunrise is 1 hour, 48 minutes later at 6:55 AM on January 12. The earliest sunset is at 5:08 PM on December 1, and the latest sunset is 1 hour, 55 minutes later at 7:03 PM on July 2.

Daylight saving time (DST) is not observed in Sishan during 2024.

The figure below presents a compact representation of key lunar data for 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.

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.

Sishan experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 4.3 months, from May 18 to September 28, during which time the comfort level is muggy, oppressive, or miserable at least 24% of the time. The month with the most muggy days in Sishan is July, with 29.6 days that are muggy or worse.

The month with the fewest muggy days in Sishan is January, with 0.0 days that are muggy or worse.

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 Sishan does not vary significantly over the course of the year, remaining within 0.3 miles per hour of 3.3 miles per hour throughout.

The predominant average hourly wind direction in Sishan varies throughout the year.

The wind is most often from the south for 4.0 months, from April 2 to August 3, with a peak percentage of 51% on July 8. The wind is most often from the east for 8.0 months, from August 3 to April 2, with a peak percentage of 39% on January 1.

To characterize how pleasant the weather is in Sishan throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Sishan for general outdoor tourist activities is from mid July to late September, with a peak score in the last week of August.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Sishan for hot-weather activities is from early July to mid August, with a peak score in the last week of July.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

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).

The growing season in Sishan typically lasts for 7.3 months (223 days), from around March 31 to around November 9, rarely starting before March 12 or after April 19, and rarely ending before October 20 or after November 28.

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.

Based on growing degree days alone, the first spring blooms in Sishan should appear around March 24, only rarely appearing before March 6 or after April 8.

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 experiences some seasonal variation over the course of the year.

The brighter period of the year lasts for 2.7 months, from June 17 to September 8, with an average daily incident shortwave energy per square meter above 5.4 kWh. The brightest month of the year in Sishan is July, with an average of 5.8 kWh.

The darker period of the year lasts for 3.2 months, from November 10 to February 18, with an average daily incident shortwave energy per square meter below 3.8 kWh. The darkest month of the year in Sishan is January, with an average of 3.4 kWh.

For the purposes of this report, the geographical coordinates of Sishan are 27.699 deg latitude, 119.060 deg longitude, and 3,212 ft elevation.

The topography within 2 miles of Sishan contains large variations in elevation, with a maximum elevation change of 3,045 feet and an average elevation above sea level of 3,754 feet. Within 10 miles contains large variations in elevation (5,207 feet). Within 50 miles also contains extreme variations in elevation (6,201 feet).

The area within 2 miles of Sishan is covered by trees (98%), within 10 miles by trees (93%), and within 50 miles by trees (74%) and grassland (13%).