Nepal has a great deal of variation in climate... and a tropical and subtropical climate exists in the Tarai Region. Outside the Tarai, however, the climate is completely different.

The remarkable differences in climatic conditions are primarily related to the enormous range of altitude within such a short north-south distance. The presence of the east-west-trending Himalayan massifs to the north and the monsoonal alteration of wet and dry seasons also greatly contribute to local variations in climate.... five climatic zones in Nepal based on altitude.

The tropical and subtropical zone of below 1,200 meters in altitude.

The cool, temperate zone of 1,200 to 2,400 meters in altitude.

The cold zone of 2,400 to 3,600 meters in altitude

The sub- arctic climatic zone of 3,600 to 4,400 meters in altitude.

The arctic zone above 4,400 meters in altitude.

In terms of natural vegetational regimes or distribution patterns, altitude again plays a significant role. Below 1,200 meters, the dominant form of vegetation consists of tropical and subtropical rain forests.