Average Weather in Trongsa Bhutan
In Trongsa, the wet season is comfortable and mostly cloudy and the dry season is cool and mostly clear. Over the course of the year, the temperature typically varies from 29°F to 70°F and is rarely below 22°F or above 75°F.
Based on the tourism score, the best times of year to visit Trongsa for warm-weather activities are from late May to late June and from early September to early October.
The warm season lasts for 4.3 months, from May 28 to October 4, with an average daily high temperature above 66°F. The hottest day of the year is August 1, with an average high of 70°F and low of 56°F.
The cold season lasts for 2.7 months, from December 11 to March 3, with an average daily high temperature below 54°F. The coldest day of the year is January 21, with an average low of 29°F and high of 50°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
In Trongsa, 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 Trongsa begins around October 4 and lasts for 7.8 months, ending around May 29. On January 24, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 88% of the time, and overcast or mostly cloudy 12% of the time.
The cloudier part of the year begins around May 29 and lasts for 4.2 months, ending around October 4. On July 25, the cloudiest day of the year, the sky is overcast or mostly cloudy 87% of the time, and clear, mostly clear, or partly cloudy 13% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Trongsa varies very significantly throughout the year.
The wetter season lasts 5.1 months, from April 16 to September 21, with a greater than 37% chance of a given day being a wet day. The chance of a wet day peaks at 73% on July 18.
The drier season lasts 6.9 months, from September 21 to April 16. The smallest chance of a wet day is 1% on December 1.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 73% on July 18.
Daily Chance of Precipitation
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. Trongsa experiences extreme seasonal variation in monthly rainfall.
The rainy period of the year lasts for 7.9 months, from March 9 to November 4, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around July 15, with an average total accumulation of 7.4 inches.
The rainless period of the year lasts for 4.1 months, from November 4 to March 9. The least rain falls around January 1, with an average total accumulation of 0.1 inches.
Average Monthly Rainfall
The length of the day in Trongsa varies over the course of the year. In 2019, the shortest day is December 22, with 10 hours, 24 minutes of daylight; the longest day is June 21, with 13 hours, 53 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:02 AM on June 10, and the latest sunrise is 1 hour, 48 minutes later at 6:49 AM on January 12. The earliest sunset is at 5:02 PM on December 1, and the latest sunset is 1 hour, 54 minutes later at 6:57 PM on July 2.
Daylight saving time (DST) is not observed in Trongsa during 2019.
Sunrise & Sunset with Twilight
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 perceived humidity level in Trongsa, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
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 Trongsa experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 6.8 months, from February 16 to September 8, with average wind speeds of more than 3.9 miles per hour. The windiest day of the year is April 3, with an average hourly wind speed of 4.7 miles per hour.
The calmer time of year lasts for 5.2 months, from September 8 to February 16. The calmest day of the year is December 8, with an average hourly wind speed of 3.1 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Trongsa varies throughout the year.
The wind is most often from the south for 8.8 months, from February 21 to November 15, with a peak percentage of 82% on July 5. The wind is most often from the north for 3.2 months, from November 15 to February 21, with a peak percentage of 49% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is in Trongsa 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 Trongsa for general outdoor tourist activities are from late May to late June and from early September to early October, with a peak score in the second week of June.
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 Trongsa for hot-weather activities is from early July to late August, with a peak score in the first week of August.
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 Trongsa typically lasts for 7.8 months (237 days), from around April 8 to around December 1, rarely starting before March 19 or after April 26, and rarely ending before November 10 or after December 21.
Time Spent in Various Temperature Bands and the Growing Season
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 Trongsa should appear around April 6, only rarely appearing before March 18 or after April 25.
Growing Degree Days
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 2.5 months, from March 15 to May 31, with an average daily incident shortwave energy per square meter above 6.6 kWh. The brightest day of the year is April 14, with an average of 7.1 kWh.
The darker period of the year lasts for 2.4 months, from November 13 to January 25, with an average daily incident shortwave energy per square meter below 5.0 kWh. The darkest day of the year is December 21, with an average of 4.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Trongsa are 27.503 deg latitude, 90.507 deg longitude, and 8,422 ft elevation.
The topography within 2 miles of Trongsa contains extreme variations in elevation, with a maximum elevation change of 4,997 feet and an average elevation above sea level of 7,800 feet. Within 10 miles also contains extreme variations in elevation (10,656 feet). Within 50 miles also contains extreme variations in elevation (24,314 feet).
The area within 2 miles of Trongsa is covered by shrubs (40%), trees (35%), and cropland (25%), within 10 miles by trees (74%) and cropland (12%), and within 50 miles by trees (63%).
This report illustrates the typical weather in Trongsa, 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, Lokpriya Gopinath Bordoloi International Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Trongsa.
At a distance of 189 kilometers from Trongsa, 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 Trongsa to the nearest station, increasing from 0% at 150 kilometers to 100% at 200 kilometers. In this case, the MERRA-2 weight is 44%, making the weight assigned to the weather station 56%.
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.