Average Weather in Kathmandu Nepal
Kathmandu has a warm temperate climate with dry winters and hot summers. The temperature typically varies from 37°F to 84°F over the course of the year, and is rarely below 33°F or above 89°F.
The warm season lasts for 189 days, from April 5 to October 11, with an average daily high temperature above 80°F. The hottest day of the year is June 12, with an average high of 84°F and low of 67°F.
The cool season lasts for 65 days, from December 9 to February 12, with an average daily high temperature below 68°F. The coldest day of the year is January 7, with an average low of 37°F and high of 64°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
The length of the day in Kathmandu varies over the course of the year. In 2017, 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.
Hours of Daylight and Twilight
The earliest sunrise is at 5:07 AM on June 10, and the latest sunrise is 1 hour, 49 minutes later at 6:55 AM on January 11. 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 1.
Daylight saving time (DST) is not observed in Kathmandu during 2017.
Sunrise & Sunset with Twilight
In Kathmandu, 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 Kathmandu begins around September 20 and lasts for 275 days, ending around June 22. On November 5, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 93% of the time, and overcast or mostly cloudy 7% of the time.
The cloudier part of the year begins around June 22 and lasts for 90 days, ending around September 20. On August 5, the cloudiest day of the year, the sky is overcast or mostly cloudy 84% of the time, and clear, mostly clear, or partly cloudy 16% 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 Kathmandu varies very significantly throughout the year.
The wetter season lasts 118 days, from May 31 to September 26, with a greater than 32% chance of a given day being a wet day. The chance of a wet day peaks at 63% on July 18.
The drier season lasts 247 days, from September 26 to May 31. The smallest chance of a wet day is 1% on November 20.
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 63% 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 in the year. Kathmandu experiences very significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 204 days, from April 9 to October 30, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around July 18, with an average total accumulation of 7.3 inches.
The rainless period of the year lasts for 161 days, from October 30 to April 9. The least rain falls around November 21, with and average total accumulation of 0.1 inches.
Average Monthly Rainfall
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.
Kathmandu experiences very significant seasonal variation in the perceived humidity.
The muggier period of the year lasts for 132 days, from May 27 to October 6, during which time the comfort level is muggy, oppressive, or miserable at least 24% of the time. The muggiest day of the year is August 2, with muggy conditions 97% of the time.
The least muggy day of the year is December 15, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
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 Kathmandu experiences mildly seasonal variation over the course of the year.
The windier part of the year lasts for 155 days, from February 15 to July 20, with average wind speeds of more than 2.7 miles per hour. The windiest day of the year is April 13, with an average hourly wind speed of 3.4 miles per hour.
The calmer time of year lasts for 210 days, from July 20 to February 15. The calmest day of the year is December 1, with an average hourly wind speed of 2.0 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Kathmandu varies throughout the year.
The wind is most often from the west for 26 days, from March 26 to April 21, with a peak percentage of 38% on March 8. The wind is most often from the south for 180 days, from April 21 to October 18, with a peak percentage of 80% on July 20. The wind is most often from the north for 159 days, from October 18 to March 26, with a peak percentage of 48% on December 30.
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 significant seasonal variation over the course of the year.
The brighter period of the year lasts for 80 days, from March 27 to June 15, with an average daily incident shortwave energy per square meter above 6.8 kWh. The brightest day of the year is May 23, with an average of 7.6 kWh.
The darker period of the year lasts for 80 days, from November 12 to January 31, with an average daily incident shortwave energy per square meter below 4.9 kWh. The darkest day of the year is December 21, with an average of 4.2 kWh.
Average Daily Incident Shortwave Solar Energy
The area within 2 miles of Kathmandu is covered by artificial surfaces (57%) and cropland (41%), within 10 miles by cropland (42%) and trees (36%), and within 50 miles by trees (50%) and cropland (29%).
The topography within 2 miles of Kathmandu contains only modest variations in elevation, with a maximum elevation change of 230 feet, and an average elevation above sea level of 4,291 feet. Within 10 miles contains extreme variations in elevation (6,155 feet). Within 50 miles also contains extreme variations in elevation (24,052 feet).
This report illustrates the typical weather in Kathmandu, 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, Tribhuvan International Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Kathmandu.
At a distance of 4 kilometers from Kathmandu, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records.
The station records are are corrected for the elevation difference between the station and Kathmandu according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
Please note that the station records themselves may additionally have been back-filled using other nearby stations or the MERRA-2 reanalysis.
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 .