In this work, two countries are intentionally chosen in different zones in order to compare the results. One of them is Turkey near the north pole and the other is in the south pole. Global solar radiation data for both zones are analyzed and presented in a form suitable for their use by engineers. Three different models besides our model for monthly average data are applied to predict monthly average global radiation with acceptable accuracy in both zones for both cities. The coastline region is taken into account. Our quadratic relation that we obtained seems to be used to estimate monthly average daily global solar radiation for both zones for the coastline region where the measured data is scarce.