I need maximum and minimum temperature data of each countries.
I searched a lot but could not find the values.
Could you give links if it is possible?
There are several ways that you could possibly achieve this. My personal favorite is using RSS feeds to pump out the data to url that you can link to. WeatherBug has a great RSS feed that you can customize and setup for each country you want to then pass the values to a page, email, whatever you like.
Here is the starting point for the RSS. you can get other examples and code snippets from this site as well. http://weather.weatherbug.com/support/rss.html