I was re-directed to; https://www.wunderground.com/ I had no problem with the site.

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

You can try these steps in case of issues with web pages:

You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

• hold down the Shift key and left-click the Reload button
• press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• press "Command + Shift + R" (Mac)

Clear the cache and remove the cookies from websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Clear the cache":

• Options/Preferences -> Advanced -> Network -> Cached Web Content: "Clear Now"

"Remove the cookies" from websites that cause problems.

• Options/Preferences -> Privacy -> "Use custom settings for history" -> Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems
• https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

Hi FredMcD, Thank you for your reply. Starting in safe mode made no difference. Actually, it seemed to get worse when I did. But, when I started in safe mode (shift key start Firefox) I didn't see any thing on my screen to show I was in safe mode. Nonetheless, I did start in safe mode when I got the safe mode screen. Any suggestions? If you went to weatherundergound and had no problems? Did you get the drop down message a web page is slowing down your browser? Or, did the site just take for ever to load? Thanks, FredMcD.

Are you using extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block (wanted) content (e.g. Adblock Plus, NoScript, Ghostery, uBlock Origin)? If you do then make sure these extensions do not block (wanted) content.

• make sure your extensions and filters are updated to the latest version

Hi cor-el, thank you for your reply. I'm not using any Add-ons. I'm using only one extension, a ad blocker called uBlock Origin. But, when I disabled the blocker it made no difference in the sites performance, which is a lot slower than before, and as I mentioned, I keep getting the drop down error message at the top of the screen saying " a web page is slowing down your browser" and then it has two options, either "stop it" or wait. When I click on "stop it", the site locks up. When I click on "wait", the site continues to operate but poorly. I never used to get that message, and I suspect that error message coincides with the site's poor performance lately. I really haven't done anything different to my computer to effect a web site acting strangely. And again, I haven't been able to get any help from weatherundergrounds help section, even though I have tried numerous times. I do have this sneaky suspicion, that weatherunderground is doing something to their site to cause the problem, maybe updating something? But, when you log onto the site, cor-el, do you get a slow reacting site, and do you get the same drop down message at the top, that states " a web page is slowing down your browser? If not, then it is my system, and not the site itself, which would be confusing. Any further suggestions, cor-el? I do appreciate any help. Thank you.

Try to create a new profile to test if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Hi cor-el, thank you for your reply. I finally got a response from the weatherunderground help desk. They informed me that they are "updating" their site. But, they seem to be very illusive about if they have a problem. It seems they are having a problem with certain aspects of their site, but again, they don't want to admit to a problem, which I believe they are having, and the weathreunderground tech seemed to be eluding to? They did ask specifically what my issues are, and I responded to them with my specific problems. I haven't heard back from them yet. So, maybe it might be best to wait for their reply before I make changes with my system. But, if you think, cor-el I can make a profile change and it will NOT effect my system adversely, is that a option? Or, should I just wait until I hear back from weatherunderground? Appreciate your help and suggestions, cor-el. Thank you.

Creating a new profile will not change the old one.

FredMcD, thank you for your reply. I will wait until I hear from weatherunderground before proceeding. If they are the problem, I really don't want to mess with my browser.