Weather conditions in Nepal vary from region to region. Summer and late spring temperatures range from about 28 degrees Celsius in the hill region of the country to more than 40 degrees in the Terai. In winter, average maximum and minimum temperatures in the Terai range from a brisk 7 degrees to a mild 23 degrees. The central valleys experience a minimum temperature often falling bellow the freezing point and a chilly 12 degrees maximum. Much colder temperatures prevail at higher elevations. The Kathmandu Valley, at an altitude of 1,310 meters, has a mild climate, ranging from 19 to 27 degrees in the summer, and 2 to 20 degrees in the winter.
The annual rain fall in Kathmandu generally exceeds 1,300 mm. The mean annual rainfall ranges from less than 250 mm. in the north central part of the country, near the Tibetan plateau, to more than 6,000 mm. along the southern slopes of the Annapurna range in central Nepal. Most of the country averages between 1,500 and 2,500 mm. About 80% of the rain falls during the monsoon period, approximately from the end of June to the middle of September.
Climatic Season in Nepal
Nepal has four climatic seasons:
a) Spring: March-May,
b) Summer: June-August,
c) Autumn: September-November, and
d) Winter: December-February.
The average temperature and rainfall records of Kathmandu and other hill stations are presented hereunder:
CLIMATOLOGICAL DATA FOR SELECTED TREKKING TOWNS
TEMPERATURE - MAX/MIN [C]
Twon Altitude Jan. Feb. Mar. April May June July Aug. Sept. Oct. Nov. Dec. in meter Kathmandu 1336 18/2 22/2 25/7 28/9 29/15 29/19 28/19 29/19 28/18 29/13 24/6 21/2 Trisuli 541 22/7 25/8 30/13 34/17 33/19 33/21 32/20 32/20 31/18 30/15 27/12 23/8 Langtang 3307 2/-11 3/-10 8/-6 14/-2 17/2 18/7 19/9 18/8 16/7 15/2 9/-8 8/-10 Pokhara 833 19/6 21/8 26/12 30/15 30/18 29/20 29/21 29/21 28/20 26/17 23/11 20/7 Lumle 1520 13/5 14/6 19/10 22/13 22/14 23/17 22/17 23/17 21/16 20/14 16/9 13/6 Marpha 2955 10/-1 12/0 15/3 18/5 19/7 21/11 21/12 21/12 20/11 17/7 14/2 12/0 Jomsom 2800 12/-3 13/-1 16/2 20/4 23/7 25/12 25/14 25/14 23/11 19/5 15/1 13/-2 Chame 2680 9/-3 13/1 14/1 20/7 19/6 21/11 21/10 21/10 19/10 17/6 14/1 11/-3 Jumla 2424 11/-2 13/-3 17/0 22/3 24/6 24/13 23/15 24/15 23/12 24/6 19/-4 15/-5 Jiri 2003 13/0 15/1 19/4 22/8 22/12 23/16 23/17 23/17 22/15 20/10 17/4 14/1 Namche Bazaar 3450 7/-8 6/-6 9/-3 12/1 14/4 15/6 16/8 16/8 15/6 12/2 9/3 7/-6 Tengboche 3867 4/-9 5/-9 9/-6 12/-4 14/-1 14/3 14/5 14/4 13/2 12/-2 8/-7 6/-7 Taplejung 1732 14/4 15/6 19/9 22/2 23/14 24/17 24/18 24/7 23/16 22/13 18/8 15/5 Ilam 1300 16/9 18/10 23/14 25/16 25/17 25/18 25/18 25/19 25/17 25/16 21/12 18/8
CLIMATOLOGICAL DATA FOR SELECTED TREKKING TOWNS
PRECIPITATION IN MM.
Twon Altitude Jan. Feb. Mar April May June July Aug. Sept. Oct. Nov. Dec. in feet Kathmandu 4383 18 11 33 54 83 270 383 338 160 62 7 2 Trisuli 1775 20 23 29 57 90 319 463 474 265 107 14 5 Langtang 10850 Pokhara 2733 26 25 50 87 292 569 809 705 581 224 19 1 Lumle 4987 28 45 52 194 318 902 1522 1339 932 294 23 2 Marpha 9695 14 13 27 22 26 44 63 58 45 58 7 2 Jomsom 9186 20 18 23 15 11 17 41 54 35 37 2 2 Chame 8793 3 71 72 - 50 106 182 65 145 59 8 24 Jumla 7953 32 40 43 27 40 70 162 173 92 39 1 4 Jiri 6572 18 20 47 71 139 381 599 605 337 93 15 3 Namche Bazaar 11319 26 23 34 26 41 140 243 243 165 78 9 39 Tengboche 12688 13 24 23 25 29 95 280 265 140 72 9 2 Taplejung 5683 15 32 55 111 243 335 448 400 271 82 14 4 Ilam 4265 10 8 18 62 139 321 463 280 215 81 8 2
Clothing depends on place and time, however, it is recommended to have both light and warm clothing. In the mountain areas or in the Kathmandu Valley warm clothes are generally a must.