Nepal has Mount Everest at more than 29,000 feet in its north, but elevations of a few hundred feet only are common at her southern border. This great diversity of terrain in a small space contributes to the country's fascination for travelers. The country is broadly divided in to three areas:
The southern, lowland plains called the Terai. This is where Chitwan National Park is located.
The central hills where altitudes range up to 7,000 to 8,000 feet. Kathmandu is located in this zone.
The high mountains, which rise steeply in the north.
Nepal has five seasons, three or four of which are suitable for tourism. It's location on the Indian subcontinent makes it subject to monsoon rains; and while trekking during monsoon has some advantages (like very few tourists), it's not what most people want.
In the mountains, of course, below-freezing temperatures are common; but the central hills are generally comfortable year-round, and the Terai is hot and tropical.
See useful charts of temperature and rainfall in Kathmandu here.
About The Mountains
EVEREST (29028 feet / 8848 meters) is named posthumously after Sir George Everest, Surveyor General of the Great Trigonometrical Survey of India. It is a great irony, since in his life Sir George was of the firm opinion that peaks should wear their original names. The peak's old names are Chomolungma (Tibetan, meaning Goddess Mother Mountain) and Sagarmatha (Nepali, meaning One Whose Forehead Touches the Sky). Now often climbed, but still never mastered.
KANCHENJUNGA (27943 feet / 8598 meters) has five summits, it's name derived from the Tibetan words for "five treasures" or "five brothers". The original inhabitants of Sikkim, south of Kanchenjunga, the Lechpas, believed that it was from Kanchenjunga's ice that the first man and woman were carved, and they also worshipped it as the place where the dead go. Today a trek to the two Base Camps (Kanchenjunga - 18 to 29 Days) isn't life threatening, but it's still plenty exciting!
MAKALU (27504 feel / 8463 meters) rises at the head of Makalu and Barun Glacier National Park, a high mountain wilderness of unsurpassed beauty. Makalu sits between Everest and Kanchenjunga (number three in height), on the Tibetan border. Of all the great peaks, Makalu is the one with the most otherworldly presence according to the Sherpa people who live in its shadow.
DHAULAGIRI (26690 feet / 8137 meters) stands along one side of the valley of the Kali Gandaki river, deepest in the world. The three and one half mile chasm was formed by the river, as the mountains rose up around it over the millenia. From Dhaulagiri to Nilgiri and Annapurna 1 on the otherside, the valley is barely four miles wide, making an almost perfect V shape.
CHO OYU (26653 feet / 8201 meters) has an almost table-top flatness at its summit. Some believe that in ancient times Padma Sambhava, Buddhism's only "saint", wrote texts with messages to save earth from a time when the world was in chaos, and buried these texts on Cho Oyu. The lamas call those texts Cho. Oyu means "turquoise", and whether Padma Sambhava's treasures are there, we know that turquoise in plenty comes out of the mountain.
AMA DABLAM (22139 feet / 6812 meters) is a favorite at Friends in High Places, though not one of the highest peaks. To western eyes the south face of the mountain looks like a priest or minister in robes holding up both hands in a blessing, but the same shape reminds easterners of a Dablam, or an amulet box used to hold a small image of a God. Ama means "mother," so Ama Dablam is "Mother's Reliquary". By either meaning it is a wonderful, poetic mountain.