1) In Windows Explorer, browse to c:\\Windows\\System32 and find“notepad.exe”
2)Right click “notepad.exe”, then choose "Run as Administrator"
3) Now you are in notepad, click File->Open, then go to c:\\Windows\\System32\\drivers\\etc
4) On the lower-right corner, you may see a dropdown box with "Text Document (*.txt)", change to "All Files" , then select "hosts" in the files list, and click "Open"
5) Now you should see the content of the hosts file, click the end of the file and add following line :
104.103.155.90 www.weather.com e7121.g.akamaiedge.net pmd-www.weather.com.edgekey.net
6) Click File->Save to save the file
7) test with http://www.weather.com in your browser.
I'm not sure if this can fix the problem, as I don't have slowness issue with www.weather.com.
Good luck!