Why won't my wifi signal go above one bar?

I'm using my iPhone 5 on iOS 6.02. Ever since I updated to 6.02 my wifi signal will not go above the first bar (or dot... Whatever). It has been in or out of many cases, on many wifi networks, at different intervals from the routers... Nothing changes the level of my signal. I don't know if I'm the only one having this issue, but it's irritating. It doesn't seem to be affecting my signal.

Can anybody help me fix this? Any ideas besides turning on and off wifi?