Question

Among equatorial, tropical and polar region where is the annual range of temperature minimum?

Answer 1

I going to assume you mean seasonal variations, and I would say that regions nearest the equator will have the smallest yearly variation in temperature.

Explanation:

The reason is that the planet receives the most direct rays from the Sun all year round at the Equator and in the zone between the Tropic of Cancer (at 23.5 degrees N Latitude) and the Tropic of Capricorn (at 23.5 degrees S Latitude).

The farther north or south you go from the Equator, the more slanted the Sun's rays are as they hit the planet -- a little in summer and a lot in winter. That's because the Earth's axis is tilted at an angle of `23.5^o` from the vertical.

From personal experience, I can tell you that I lived in Puerto Rico for a few years, and the yearly temperature there varied from about `80^o F` in January and February to about `97^o F` in summer.

When I lived in Michigan, summers could also be `97^o F`, but winters could get down to the teens - well below zero.

So:
`97^o F - 80^o F =` a range of `17^o F`, and
`97^o F - 15^o F =` a range of `85^o F`.

Here are two maps of global temperatures, one for January, one for July. Temperatures near the Equator are similar in both January and July, but at higher latitudes - temperate and polar - they are noticeably colder in winter than summer.

These maps are from a REALLY GOOD online physical geography textbook by: Ritter, Michael E. The Physical Environment: an Introduction to Physical Geography.

Here's the exact page where the maps are:
https://www.earthonlinemedia.com/ebooks/tpe_3e/temperature/explaining_global_patterns_temperature.html

General site address:
http://www.earthonlinemedia.com/ebooks/tpe_3e/title_page.html

Connie