I'm in the US and we normally have voltages (for standard households) ranging from 110V to 120V but I seem to be supplied by a voltage of 125V, as the day goes on it will fluctuate between 123-125V and I'm asking this because this (to me) doesn't seem normal.
I like it because it makes things like, portable fans run faster, (I think) makes a CFL or Fluorescent warm up faster, and much more.
The only reason on why I dislike the raise in 5V is potential reduced life of any electrical device due to a small overvolting.

Does anyone else in the US have this weird voltage?
Does anyone know why it's 125V instead of 120V?

Much of New York City is supplied from low voltage networks. The nominal voltages are 125/216. My house voltage varies from 123 to 126. It was incandescent lamps that were affected the most by voltage variations. Another five volts on a lamp designed for 120 volts seriously reduced the life.

The only reason on why I dislike the raise in 5V is potential reduced life of any electrical device due to a small overvolting.

Don't worry, for vast majority of appliances it won't make any harm at all (practically all use some form of feedback keeping the output performance unchanged).
For many of them it actually means a bit less stress (practically all modern electronic, mainly the world wide universal "100..240V", induction motors will have less slip, so less losses in the rotor), the only thing that may suffer in lifetime are the incandescent. But you will be rewarded by their extra efficacy, so may theoretically use lower wattage ones. And this will save more $$ than is the cost of the more frequent replacements.

Does anyone know why it's 125V instead of 120V?

If you are living close to a transformer which feeds more homes via a 2x120/240V cable, the extra voltage at the transformer secondary is meant to compensate the voltage drop across the length of that cable (here is very common for the homes living close to the transformer to have 240V, while the ones on the far end have barely 220V in their sockets, all with "230V" mains).
Or your feed/transformer/wiring has a bit higher impedance (far from the distribution substation, long feed from the pole transformer to the house, minimalistic transformer size because feeding just your home), so the extra voltage is intended to compensate for the drop in case your home will draw all reserved power the feed is designed for (so the voltage wont droop too much below 110V).

This is normal. I get 119v usually.

Line voltage can vary enormously, depending on many things; distance from the substation, number of customers on the same run of cable, type of cable used, etc. For this reason, there will always be a tolerance range specified by either government or the supply authority. Here in the UK, this is 240V 50Hz + 6% / - 10%. This can mean the voltage at the customer's premises can vary quite considerably, from 216V to 254.4V..!

I posted in another thread about an interesting website I found about the variations in UK and European voltages, see here.

Quoting a short section of it:

"Although the ideal would have been to have a single voltage there were too many political, financial and technical obstacles to reduce UK voltage to European levels or to increase European voltage to UK levels, so a new standard was created to cover both. This was achieved by changing the tolerances of previously existing supply standards. UK voltage  to 240VAC + 6% and - 10% and European to 220VAC +10% and -6%  (thereby creating a manageable overlap) and we would call these two combined 230VAC, despite the fact that nobody was intentionally generating at 230VAC!"

Our line voltage here is actually around 245-247V, I believe this is the case due to there being a substation literally across the street, which we can see from our kitchen window. However half a mile down the road it would probably be a bit lower.

The article goes on to say that while most equipment should work fine across the variations found, some appliances designed for 220V might not like 254V applied to them, despite both voltages being within specification, so the advice seems to be use common sense.

It's not a bit different than normal, it's normal to fluctuate all the time...as loads on the lines change and demand increases or decreases your voltage will change.

Last time i checked, the voltage where i live jumped around between 120v and 125v

Quoting a short section of it:

"Although the ideal would have been to have a single voltage there were too many political, financial and technical obstacles to reduce UK voltage to European levels or to increase European voltage to UK levels, so a new standard was created to cover both. This was achieved by changing the tolerances of previously existing supply standards. UK voltage  to 240VAC + 6% and - 10% and European to 220VAC +10% and -6%  (thereby creating a manageable overlap) and we would call these two combined 230VAC, despite the fact that nobody was intentionally generating at 230VAC!"

Well, this may have been valid for the western part of Europe. For our standards it was tightening the limits: From 220V -10/+15% to the 230V -10/+5%.
And mainly the smaller villages did "use" the whole tolerance band due to the voltage drops, so the standard change meant their power network had to be upgraded.
However that wide fluctuations was really making big troubles (and there mainly the low voltage end), so to have a technically sound installation the system needed the upgrade regardless of the standard.

Otherwise the meaning of the "unified standard" was not to change the real voltages anywhere (that is practically impossible - as it would require replacing 5..10 transformers in a smaller town all at once, so few days with the electricity shut down), but to create a standard, where all existing installations fit well (well, except the ones I described earlier, but those needed to be upgraded anyway).
You may ask why to modify existing stricter standards: The reason is not the power network in any place, but to make sure any local equipment maker makes his designs so they really work everywhere in the EU, across all the local voltage levels.

I think the same (or very similar) situation is in the US: Some states have "115V", some "120V", but the tolerance bands of both are actually exactly equal, so the difference is really only in the label.

I've >220V in my room at my hostel. Sometimes even >210V, despite the voltage at the input of the electricity meter is 230V. Sometimes my UPS would boost the voltage to my computer and monitor by 30V:

The line voltage here at work is higher than usual-the power company says we are the first customer on the 115Kv 3p line.So we have to set transformer taps at the highest primary voltage.We should get a nominal 4160V 3 ph-0but it can be as high as 4400V! One of our transmitters has a phase-voltage monitor that shuts it down if the line voltage is over 5% too high.Usually this happens at night on seasons where heat or cooling isn't used.The line voltage tolerance in the US can be 10% high or low.All appliances are designed to cope with this.The German made AEG transmitter is not.The monitor is set at its max setting.Figure the voltage tolerance in Germany must be tighter.Maybe someone from Germany can comment on this.Another example is the 208/120V transformer system here that steps 4160 to 208/120 for gen building use can be at 210-212 V.Read off the meter at the 500Kva stepdown transformers.We have 2 transmformers-if one fails it gets switched to the second by a transfer switch like on a genset.You can switch manually-but don't want to do this-!!!

I don't know how exactly how in Germany, but here two things are common (and I would guess with the way these things are managed it is just the same "mentality" here as in Germany):
- Practically all lines above 22kV come from transformers with on load adjustable output voltage. The reason is exactly "just" to compensate load/generation balance on that leg. Many 22kV outputs are fed from similar devices, but not all.
- Installations requiring tight voltage tolerances, like railway/tram/trolleybus feeds, mining transportation systems, but as well data-centers, transmitters and similar are all equipped with their own voltage stabilization systems (either controlled regulating rectifiers, or adjustable transformers) as well.

So my guess:
The transmitter itself is designed assuming it will be fed from such stabilized power source. Or at least its "basic" offerings.
I would guess AEG is/was offering the stabilization substation as well, but that would "lower the Made-In-USA content".
So someone decided the transmitter will be ordered without the substation, but either forget its required "features list" or (my bet) thought because of the "first customer on the line", the voltage variation won't be that high so he may get away with that. And as you wrote, it does not work...

The thing is, I can not imagine, how a device like high power transmitter could be made to run economically without very precisely stabilized supply. The thing is, the regulation require quite accurate output power levels, the energy cost (we are talking about MW consumption permanently ON) require it to operate at as low losses as possible. And that just excludes poorly regulated supply of the final stage (if the final stage would have to "absorb" +/-10% supply variation on its own, its efficiency would be 10% lower in average and that means triple losses when the supply goes to its high limit - way too much to technically handle in a reasonable way).
That makes me think the same problems would be with any transmitter, include some domestic made. Because I doubt anyone would offer such thing inherently so tolerant, it would be just way too expensive at least.

Our AEG/Telefunken transmitter was built in Munich,Germany in 1985.We also have a Swiss Brown Boveri transmitter that has its own 220/400V regulator .Figure this should have been put in the AEG as well.We have NO voltage outages on the BBC transmitter.Both were installed in 1985 by their manufactuerers.

Nice stable 123 volts at my house and where I work.

My voltage is around 117 although I've seen 115 during high usage times.

Wow! The voltage in my room at my hostel, was 208V only at 16:45, and the UPS boost it by 30V to 238V to my computer: