Your internet is "hard wired" to the house via either your telephone line, tv cable provider, or perhaps a satellite?

If you are on dial up and using the phone line, it's most likely that weather does affect the signal somewhere along the line. While it isn't enough to take your phone service down, it can create enough noise on the line to prevent complete packets of information being transferred for internet. Make sure you have line filters on your telephone lines to rule this out. Otherwise, contact your telephone company about checking for noise. I buy replacement filters at the dollar store.

DSL can also use telephone lines via ethernet cable to modem. It's important to have line filters on ALL phones in the house to rule out line noise.

If your tv signal/cable tv signal is deteriorated during storms, and this is your provider for internet service also, then contact them to check the outside lines and connections to the house to solve this issue.

The internet around the world doesn't go "down." A site can go down, but the odds of it being the internet are really huge. If you're having problems getting online, odds are it's solution is near you. TC