🇳🇵Nepal

Nepal spans 26°22′–30°27′N as a landlocked Himalayan nation of approximately 147,516 km², stretching 885 km east–west and containing eight of the world's fourteen peaks above 8,000 m — including Mount Everest (Sagarmatha, 8,849 m, Earth's highest), Kanchenjunga (8,586 m), Lhotse (8,516 m), Makalu (8,485 m), Cho Oyu (8,188 m), Dhaulagiri (8,167 m), Manaslu (8,163 m), and Annapurna (8,091 m). This extreme topographic gradient from the tropical Terai lowlands at 60 m elevation through the temperate mid-hills to the alpine and nival Himalayan crest above 5,500 m produces a remarkable climate spectrum: humid subtropical (Cwa) and tropical monsoon (Am) in the Terai plains (Janakpur, Biratnagar, Birgunj), warm temperate (Cwb) across the mid-hills including the Kathmandu Valley at 1,400 m, alpine tundra (ET) in the high Himalaya, and permanent ice-cap (EF) above 5,500 m on Everest, Khumbu Glacier, and the great Himalayan glaciers feeding the Ganges, Koshi, and Karnali river systems.

Kathmandu averages 3°C in January and 24°C in July with roughly 1,454 mm of annual precipitation concentrated overwhelmingly in the June–September southwest monsoon (80% of yearly total). Pokhara at 827 m records 11°C in January and 25°C in July with approximately 3,350 mm — one of the wettest cities in South Asia due to orographic monsoon enhancement by the Annapurna massif.

Janakpur and Biratnagar in the Terai register 10°C in January and exceed 30°C in May–June with 1,200–1,500 mm annual precipitation. Above 5,500 m, permanent snow and ice persist; Everest Base Camp at 5,364 m averages −17°C in winter. Nepal's monsoon climate includes significant flood events. September 2024 Kathmandu floods killed over 200 people. The June 2021 Melamchi flash flood caused damage to critical infrastructure.

In May 2013, the Seti River experienced a glacial-lake-outburst flood (GLOF), resulting in significant casualties. The August–September 2017 Terai floods inundated extensive areas of the lowlands. Glacial lake hazards are present: Imja Lake and Tsho Rolpa Lake are identified as high GLOF risks, and the Khumbu Glacier retreats approximately 20–30 m annually.

Our archive covers 15 Nepalese cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Nepalgunj, around 32.1°C, while Pokhara records the coldest January nights near 4.8°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.1°C.