Nepal Weather by Altitude

Himalayan Region Weather

Nepal's Himalayan region is characterized by diverse weather patterns, driven by its varied altitudes and geography, ranging from subtropical to alpine climates. Temperature and precipitation patterns show considerable regional variations, which impact both daily life and tourism activities.

• Average Temperatures in the Himalayan Region

• Average Annual Temperature: 4–8°C in the mountains, with temperatures below zero in higher altitudes year-round (Kumar, 2020).
  Maximum Temperature: The annual mean maximum temperature varies from 4–8°C, with peaks reaching 12–16°C during the monsoon.
  Minimum Temperature: The minimum temperature ranges from -6°C to -10°C, dropping below -10°C in winter.

• Rainfall Trends

• Average Rainfall: Varies from 50 mm to 5000 mm, with the central region receiving the highest (Dawadi et al., 2020).
  Monsoon Dominance: Over 80% of Nepal’s annual rainfall occurs during the monsoon season (Phuyal et al., 2023), and it is the same for Himalayan Region.
  Precipitation Trends: Post-monsoon rainfall is decreasing in recent years, while there is an increasing trend in rainfall in the far western and mountain regions.
  Humidity: High humidity levels are common in areas like Sagarmatha National Park (Laiolo, 2004; Adhikari & Pradhananga, 2022).

• Impact of Weather on Tourism

  Trekking Hazards: Trekking and mountaineering are significantly affected by extreme weather conditions.
  Khumbu Region: Weather is particularly unpredictable here, with clear mornings and drastic weather shifts in the afternoon (Paudel et al., 2022).
  High Altitude Sickness: Weather conditions like temperature, wind speed, and air pressure are linked to the risk of altitude sickness.
  Mount Everest: Trekkers to Everest Base Camp face extreme conditions like snowfalls, high winds, and rapid temperature changes (Adhikari & Pradhananga, 2022).
  Operational Challenges: Unpredictable weather results in delays and increased operational costs for trekking expeditions, particularly at high altitudes where conditions can rapidly worsen (Adhikari & Pradhananga, 2022).

• High Altitude Trekking Conditions

• Khumbu Region: The alpine climate here experiences snow in winter and rain in summer (Adhikari & Pradhananga, 2022). Trekkers face risks from rock and ice falls, landslides, and altitude sickness, worsened by limited oxygen and extreme weather.
  Crevasses: Crevasse risks are heightened in summer, particularly in alpine regions (Adhikari & Pradhananga, 2022).

• Mid-Hills Region Weather 

• The Mid-Hills (Middle Mountains) of Nepal experience a temperate climate influenced by the varying altitudes and topography. This region is marked by distinct seasonal weather patterns, varying temperatures, and significant rainfall.

• Temperature in Nepal's Mid-Hills

• Average Temperatures:
  Winter: Max temperature of 4-8°C, with lows dropping below 0°C at night.
  Summer: Max temperature of 24-28°C, with highs reaching 21-28°C in lower elevations (Saha et al., 2024).

• Elevation Impact:

• Temperatures decrease with higher altitudes.
  Diurnal temperature variations are more significant, especially in winter (Adhikari & Devkota, 2016).
  The temperature lapse rate in the region is -0.51°C per 100 meters of altitude (Karki et al., 2015).

• Rainfall Patterns

• Annual Precipitation:
  Average rainfall: Around 2700 mm annually, with Pokhara receiving over 5000 mm (Karki et al., 2016).
  Monsoon (June-September): The wettest season, contributing the most to total rainfall (Joshi et al., 2019).
  Precipitation Trends: Increasing rainfall during the pre-monsoon and monsoon seasons, with some regions showing more rainy days (Adhikari & Mathema, 2023).

• Extreme Weather:
  The western Mid-Hills are increasingly experiencing more extreme rainfall events (Talchabhadel et al., 2018).
  Pokhara and Lumle receive some of the highest rainfall in Nepal (Adhikari & Mathema, 2023).

• Seasonal Breakdown of Mid-Hills Climate

• Pre-Monsoon (March-May): Increasing humidity and cloud formation (Sharma & Paudel, 2021).
  Monsoon (June-September): Heavy rainfall, significantly affecting agriculture (Sharma & Paudel, 2021).
  Post-Monsoon (October-November): Cooler and drier conditions.
  Winter (December-February): Cold, dry conditions with occasional frost. Fog is common, especially in the valleys, but less intense than in the Terai (Shrestha, 2018).

• Winds and Weather Phenomena

• Winds: Strong diurnal winds are common, particularly in winter and spring, driven by thermal gradients (Bista, 2023).
  Landslides: These are common during the monsoon season due to heavy rainfall (Awasthi & Owen, 2020).
  Flooding: Flash floods in low-lying areas, especially during the monsoon (Kharel, 1997).
  Fog: Frequent in lower valleys, especially in winter (Shrestha, 2018).

• Hazards and Risks in the Mid-Hills

• Landslides and Soil Erosion: Steep terrains are highly vulnerable to landslides during the monsoon (Kharel, 1997).
  Unpredictable Weather: Weather variability disrupts daily life and agricultural activities (Adhikari & Devkota, 2016).

• Tourism and Outdoor Activities

• Best Seasons: Spring and autumn are ideal for outdoor activities like trekking, offering mild, stable weather (Laiolo, 2004).
  Monsoon Challenges: Heavy rainfall disrupts trekking and outdoor activities (Kharel, 1997).
  Weather Disruptions: Unpredictable weather can delay transportation, affecting the tourism experience (Kharel, 1997).

• Key Climate Facts for the Mid-Hills:

• Average temperature range: 4-8°C in winter to 24-28°C in summer.
  Annual rainfall: 2700 mm, with regions like Pokhara receiving over 5000 mm.
  Monsoon months: June-September are the wettest months.
  Fog: Common in valleys during winter, especially in lower regions.
  Warming trend: Increasing temperatures, especially at higher altitudes.

• Terai Region Weather

• The Terai region of Nepal, a flat plain at elevations of 60-200 meters above sea level, experiences a humid subtropical climate with distinct seasonal variations (Shrestha et al., 2018). This region is an extension of the Indo-Gangetic Plain, marked by hot, humid summers and mild winters, influencing daily life and agriculture significantly.

• Temperature

• Hot Summers: Average maximum temperatures range from 24-28°C, with peak temperatures reaching up to 35°C (Saha et al., 2024; Pranil, 2017).
  Cool Winters: Temperatures drop to 5-10°C during winter months, with mild daytime conditions and colder nights (Shrestha et al., 2022; Kumarjit et al., 2024).
  Daily Temperature Fluctuations: A decrease in daily temperature range is observed during winter due to frequent fog (Baidya et al., 2008).

• Rainfall Patterns

• Monsoon Influence: Over 80% of annual rainfall occurs during the monsoon season (June to September) (Shrestha et al., 2018; Sharma et al., 2021) throughout the country. This is also true for the Terai region.
  Annual Rainfall: Total rainfall in the Terai region can range from 300-2700 mm (Kumarjit et al., 2024).
  Westerly Winds: Besides the monsoon, winter rainfall is also influenced by westerly winds (Sharma et al., 2021).

• Fog and Cold Waves

• Fog: Dense fog is a common occurrence, especially from November to February, with peak fog events in December and January (Shrestha et al., 2018; Manandhar, 2006).
  Visibility: Fog often reduces visibility to less than 200 meters, especially in the western Terai.
  Duration: The region experiences 24-56 foggy days per year, with foggy hours ranging from 71 to 169 hours across different stations.
  Cold Waves: The Terai experiences cold waves during December to February.
  Cold wave days range from 9.2 to 13.8 days per year, with extreme cold waves occurring for 1.4 to 3.8 days annually (Shrestha et al., 2022).
  Cold and extreme cold wave days are often coincident with foggy days, leading to a significant temperature drop.

• Seasonal Characteristics

• Winter (December - February): Cool with fog and cold waves.
  Pre-Monsoon (March - May): Increasing temperatures and humidity.
  Monsoon (June - September): Hot, humid, and rainy, with the heaviest rainfall.
  Post-Monsoon (October - November): Cooler and drier, with a slight drop in humidity.

• Summary Tables

Temperature across the 3 regions

Rainfall patterns across the 3 regions

Seasonal weather breakdown across the 3 regions

Temperature fluctuation and fog across the 3 regions

References

Adhikari, T. R., & Pradhananga, D. (2022). Sensitivity of High-altitude Sickness and Death with Meteorological Variables: A Case Study of Khumbu Everest Region in Nepal. Journal of Tourism and Himalayan Adventures, 4(1), 84-93.

Awasthi, R. P., & Owen, J. S. (2020). Observed Climate Extreme in Nepal. The Geographic Base, 7, 1-14.

Dawadi, B. (2017). Climatic records and linkage along an altitudinal gradient in the southern slope of Nepal Himalaya. Journal of Nepal Geological Society, 53, 47-56.

K.C., A. (2017). Climate change and its impact on tourism in Nepal. Journal of Tourism and Hospitality Education, 7(0), 29-38.

Kumar, S. (2020). Climate conditions and variability over Nepal during 1951-2020. National Centre for Medium Range Weather Forecasting.

Phuyal, R., Devkota, T., Gautam, R., & Bhattarai, R. (2023). Climate change impact on tourism in Nepal and its resilience strategies. Nepal Public Policy Review, 5(1), 1-19.

Shrestha, S., et al. (2021). Cold wave climatology and its impacts on agriculture over the Terai region of Nepal. Natural Hazards, 112(2), 1321-1342.

Laiolo, P. (2004). The impacts of climate change on biodiversity and ecosystems in the Himalayas. Environmental Conservation Journal, 23(3), 42-51.

Adhikari, T. R., & Devkota, L. P. (2016). Climate Change and Hydrological Responses in Himalayan Basins, Nepal. In R. Singh, U. Schickhoff, & S. Mal (Eds.), Climate Change, Glacier Response, and Vegetation Dynamics in the Himalaya (pp. 9–13). Springer, Cham.

Bista, R. B. (2023). Forecasting Climate Variability in Nepal. SAINSMAT: Journal of Applied Sciences, Mathematics, and Its Education, 12(1), 8–20.

Joshi, A. R. (2019). Climate change in Lamjung District, Nepal: meteorological evidence, community perceptions, and responses. Environmental Research Communications, 1(3), 031004.

Karki, R., Talchabhadel, R., Aalto, J., & Baidya, S. K. (2016). New climatic classification of Nepal. Theoretical and Applied Climatology, 125(3-4), 799-808.

Shrestha, S. (2018). Fog characteristics in Terai region of Nepal (Doctoral dissertation, University of Melbourne).

Talchabhadel, R., Karki, R., Thapa, B. R., Bhattarai, K., & Khanal, N. R. (2018). Spatio-temporal variability of extreme precipitation in Nepal. International Journal of Climatology, 38(10), 4296-4313.

Baidya, S. K., Shrestha, M. L., Sheikh, M. M. (2008). Trends in daily climatic extremes of temperature and precipitation in Nepal. Journal of Hydrology and Meteorology, 5, 38-51.

Baral, N. (2005). Resources use and conservation attitudes of local people in the western Terai landscape, Nepal. FIU Electronic Theses and Dissertations, 1387.

Dawadi, B., Acharya, R. H., Lamichhane, D., Pudasainee, S., & Shrestha, I. K. (2020). A Short Note on Linkage of Climatic Records between Terai and Mid-mountain of Central Nepal. Journal of Geographical Research, 3(4), 27-39.

Kumarjit, S., Thota, M. S., & Ashrit, R. (2024). Climate analysis over Nepal. National Centre for Medium Range Weather Forecasting, Ministry of Earth Sciences, India.

Manandhar, K. B. (2006). The fog episode in Southern Terai Plains of Nepal: some observations and concepts. Journal of Hydrology and Meteorology, 3, 95–99.

Saha, K., Thota, M. S., & Ashrit, R. (2024). Climate analysis over Nepal. National Centre for Medium Range Weather Forecasting, Ministry of Earth Sciences, India.

Shrestha, S., Peel, M. C., & Moore, G. A. (2022). Cold waves in Terai region of Nepal and farmer’s perception of the effect of fog events and cold waves on agriculture. Theoretical and Applied Climatology, 151(1-2), 29-45.