The USA is the country that has the largest number of climates than any other country or we can also say that the US has great climatic diversity. Following are the regions for the climate changes in the US:
1. Northwest Pacific.
2. Midwest.
3. Northeast.
4. Mid/South Pacific.
5. Southwest; the hottest region of the United States
6. Southeast; hot and dry during the summer but mild during the winter.
These 6 climatic regional variation shows that the US is very diverse with respect to the climatic changes.
Although more complex animals like invertebrates and multi-celled organisms began to appear, it was very late compared to the original, simpler organisms for which the Precambrian time is characterized by.
