Climate and Average Weather Year Round in Chúc Sơn Vietnam

In Chúc Sơn, the wet season is hot, oppressive, and overcast and the dry season is comfortable, humid, and mostly clear. Over the course of the year, the temperature typically varies from 57°F to 93°F and is rarely below 49°F or above 99°F.

Based on the tourism score, the best times of year to visit Chúc Sơn for warm-weather activities are from early February to early April and from late October to late December.

The hot season lasts for 4.7 months, from May 3 to September 23, with an average daily high temperature above 88°F. The hottest month of the year in Chúc Sơn is June, with an average high of 92°F and low of 79°F.

The cool season lasts for 2.6 months, from December 10 to February 29, with an average daily high temperature below 72°F. The coldest month of the year in Chúc Sơn is January, with an average low of 58°F and high of 68°F.

In Chúc Sơn, the average percentage of the sky covered by clouds experiences extreme seasonal variation over the course of the year.

The clearer part of the year in Chúc Sơn begins around October 3 and lasts for 7.0 months, ending around May 3.

The clearest month of the year in Chúc Sơn is February, during which on average the sky is clear, mostly clear, or partly cloudy 68% of the time.

The cloudier part of the year begins around May 3 and lasts for 5.0 months, ending around October 3.

The cloudiest month of the year in Chúc Sơn is June, during which on average the sky is overcast or mostly cloudy 92% 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 Chúc Sơn varies very significantly throughout the year.

The wetter season lasts 5.1 months, from May 2 to October 6, with a greater than 30% chance of a given day being a wet day. The month with the most wet days in Chúc Sơn is August, with an average of 16.9 days with at least 0.04 inches of precipitation.

The drier season lasts 6.9 months, from October 6 to May 2. The month with the fewest wet days in Chúc Sơn is January, with an average of 1.9 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 Chúc Sơn is August, with an average of 16.9 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 56% on August 24.

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. Chúc Sơn experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in Chúc Sơn. The month with the most rain in Chúc Sơn is August, with an average rainfall of 8.8 inches.

The month with the least rain in Chúc Sơn is February, with an average rainfall of 0.5 inches.

The length of the day in Chúc Sơn varies over the course of the year. In 2024, the shortest day is December 21, with 10 hours, 52 minutes of daylight; the longest day is June 21, with 13 hours, 24 minutes of daylight.

The earliest sunrise is at 5:15 AM on June 7, and the latest sunrise is 1 hour, 21 minutes later at 6:36 AM on January 17. The earliest sunset is at 5:14 PM on November 26, and the latest sunset is 1 hour, 28 minutes later at 6:42 PM on July 4.

Daylight saving time (DST) is not observed in Chúc Sơn 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.

Chúc Sơn experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 9.0 months, from February 27 to November 25, during which time the comfort level is muggy, oppressive, or miserable at least 36% of the time. The month with the most muggy days in Chúc Sơn is July, with 31.0 days that are muggy or worse.

The month with the fewest muggy days in Chúc Sơn is January, with 5.0 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 Chúc Sơn experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 4.6 months, from January 6 to May 26, with average wind speeds of more than 6.4 miles per hour. The windiest month of the year in Chúc Sơn is March, with an average hourly wind speed of 7.6 miles per hour.

The calmer time of year lasts for 7.4 months, from May 26 to January 6. The calmest month of the year in Chúc Sơn is August, with an average hourly wind speed of 5.1 miles per hour.

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

The wind is most often from the south for 5.6 months, from March 14 to September 3, with a peak percentage of 61% on July 2. The wind is most often from the east for 1.9 weeks, from September 3 to September 16 and for 2.7 months, from December 22 to March 14, with a peak percentage of 35% on September 15. The wind is most often from the north for 3.2 months, from September 16 to December 22, with a peak percentage of 44% on November 1.

Chúc Sơn 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 water temperature experiences some seasonal variation over the course of the year.

The time of year with warmer water lasts for 4.8 months, from May 22 to October 17, with an average temperature above 82°F. The month of the year in Chúc Sơn with the warmest water is August, with an average temperature of 85°F.

The time of year with cooler water lasts for 3.3 months, from December 22 to March 31, with an average temperature below 71°F. The month of the year in Chúc Sơn with the coolest water is February, with an average temperature of 68°F.

To characterize how pleasant the weather is in Chúc Sơn 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 times of year to visit Chúc Sơn for general outdoor tourist activities are from early February to early April and from late October to late December, with a peak score in the last week of November.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best times of year to visit Chúc Sơn for hot-weather activities are from late March to early May and from late September to mid November, with a peak score in the second week of October.

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).

Temperatures in Chúc Sơn 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.

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 1.7 months, from March 22 to May 11, with an average daily incident shortwave energy per square meter above 5.3 kWh. The brightest month of the year in Chúc Sơn is April, with an average of 5.6 kWh.

The darker period of the year lasts for 2.3 months, from November 22 to February 1, with an average daily incident shortwave energy per square meter below 4.2 kWh. The darkest month of the year in Chúc Sơn is December, with an average of 4.0 kWh.

For the purposes of this report, the geographical coordinates of Chúc Sơn are 20.924 deg latitude, 105.702 deg longitude, and 52 ft elevation.

The topography within 2 miles of Chúc Sơn contains only modest variations in elevation, with a maximum elevation change of 223 feet and an average elevation above sea level of 37 feet. Within 10 miles contains only modest variations in elevation (945 feet). Within 50 miles contains very significant variations in elevation (5,387 feet).

The area within 2 miles of Chúc Sơn is covered by cropland (62%), trees (15%), grassland (13%), and shrubs (10%), within 10 miles by cropland (58%) and grassland (16%), and within 50 miles by cropland (46%) and trees (25%).