I see. But its only in the UK. That will be cool if it was in the US.

There is digital radio elsewhere in the world, but it's much the same. And with the low bitrates they use, it's not anywhere near as good as wideband FM.

I tried a scan through the AM band this morning (lights are ON) ... got a dozen or so stations, all had static/noise in the background (varing amounts from 'just some', to 'a fair bit')

I see. But its only in the UK. That will be cool if it was in the US.

In the US we have HD-Radio instead.
All you need is a HD-Radio tuner to pick up the digital signals (both FM & AM), but
Your existing station stations need to broadcast the 'HD' signal (many but not all do, and it varies allot by where you live)
You need to be close enough to the transmitter to get a perfectly clear signal
If you have lights with electronic ballasts, they will probably kill the 'HD' portion of the transmission. 

One of the things I DON'T like about LED & Fluorescent is the RF Interference (Radio frequency) they put off. 

One of the things I DON'T like about LED & Fluorescent is the RF Interference (Radio frequency) they put off. 

Yeah, I tried that, and it puts out a 60Hz sound if you put the AM radio near an CFL or LED bulb.

But of course that incandescent and halogen don't put out interference, because they don't have electronic circuits in them, just a filament wire.

Flourescent and HID lights that don't have electronic ballasts usually don't cause RFI-maybe a pop or crackle in a nearby radio when the lamp is first struck.

I tried a scan through the AM band this morning (lights are ON) ... got a dozen or so stations, all had static/noise in the background (varying amounts from 'just some', to 'a fair bit')

Tonight I did another scan through the AM band...got 15 stations, some came in pretty clear too, and one even can perfectly, well enough that even the HD/Digital signal came in. Even for just a talk station you could tell the increase in quality.
 

I tried AM on my radio in my car again as I was driving. There was a thunderstorm and flashes of lightning often and it indeed had the popping noise whenever there was a bolt of lightning. I tried scanning the channels but only 3 AM stations would come in. One had a weird whistling noise the whole time and I'm not sure if it had to do with the storm or not.

But I'm pretty sure I heard lightning on FM as well before, when I was listening and there happened to be a heavy thunderstorm.

Yup you will hear static from lightning on FM from time to time. 

These are the programs I listen to on AM

Saturday:
http://www.drive-radio.com/
http://aroundthehouse.com/
https://www.sportsmanofcolorado.com/

Weekdays:
https://www.daveramsey.com/show
https://www.stewardship.com/
Sometimes weekdays:
https://khow.iheart.com/featured/the-troubleshooter/about/

One had a weird whistling noise the whole time and I'm not sure if it had to do with the storm or not.

I don't think so. Storm always makes just cracking sounds, nothing else.
The whistling could have two reasons:
A nearby station. Its side band entering the band of your reception, or the HD part goes past the demodulator, mainly the older envelope ones (a peak rectifier) on wide IF bandwidth radios are sensitive on that; modern radios use average (the circuit makes an "absolute value" from the signal, so turns negative halves to positive, and then use a low pass filter; practically all major ICs are using this type, because it is the easiest one to integrate - requires minimum passive components, because those are very expensive to integrate on chip) type of detector, which is inherently more immune towards this.
Other reason could be your car causing RF interference in some bands (data links between different ECU's). E.g. common CAN protocol tends to generate noise on the harmonics of 250kHz, etc.

I see. But its only in the UK. That will be cool if the US have DAB stations.

DAB is an European digital broadcasting, equivalent to the HD radio extension in the US.
The main difference is, the US has a single band regulator (FCC), so it was rather easy for them to reshuffle the licenses to free up some space around each major station so they may include the digital stream there.
In Europe the regulation is distributed across all the individual states, each of them "protecting their frequencies", so any more significant reshuffling becomes politically impossible. So for digital radio broadcasting was reserved a separate band (former higher end of VHF TV bands), so instead of transitioning to the digital in the present bands, the digital service is set up separately. It has its advantages and disadvantages. Disadvantages are, you have no possibility of parallel analog/digital broadcasting as in the US.
On the other hand the digital part does not bear the burden of the analog predecessors (to not interfere with the analog part in the US poses quite severe limitation on the error rate/signal quality requirements because of the modulation style restrictions), because simply in the DAB band are no analog stations to care of at all (so the modulation schemes could be better optimized for the digital transmission). Plus there is more room available in the new band, what means better quality coding (better audio quality) or more robust data protection (worse signal condition tolerance) could be used.

What is sad to me, the original idea in the DVB-T of transmitting a lower resolution stream with more robust protection along with less protected, but way better fidelity "high quality stream" (it allows at least the base quality reception with very bad signal condition, while the quality improves ondce the signal becomes better; so having steps instead of a steep "digital cliff") is getting abandoned, because many operators are arguing "customers prefer no signal at all or best quality instead of gradually worsening quality". Well, I do not trust that statement at all (it is a marketing BS to just squeeze more sh***ty stations into a single multiplex stream to make more money), but the changes are being implemented (the TV appear to have lost the lower quality, more robust part already).

I'm curious, whether the DRM (a digital format for "AM" bands - so LW, MW ans SW, capable of either greater distance, more programs or "FM-like" audio quality in a standard 9kHz wide channel) will ever take off. There has been a talked lot about the present AM bands converting to digital, using even the existing infrastructure (DRM is advertised to be able to use even the nearly a century old transmitter HW by just connecting the new "carrier generator" and "modulation source" from an added computer, so suffice with very minimal investment on the existing broadcast equipment), but I've seen no commercial receiver set capable of receiving the DRM (although there are few stations already transmitting on SW using the DRM format).

We will be installing 1991 vintage SW transmitters-250Kw that can use DRM.The advantage of DRM you can use lower power-before you would have to use 500Kw.All these new Tx would need is the DRM exciter.We have tried DRM on a lower power 50Kw SW transmitter and it does work well.This Tx dates back to the 60's and works with DRM but the DRM is hard on baluns-the component that matches the transmitter coxial line to a balanced 300 ohm transmission line and antenna.Those newer Tx won't have this problem since they are newer.

The advantage of DRM you can use lower power...

It is not that you can use lower power, but usually you have to. It depends, whether your system is limited thermally (on higher power some components may overheat so that is limiting your power) or electrically (electrical limit of the power stage, voltage breakdown limits,...). If your limit is thermal, with DRM you may go to the same average power as you had with AM, the heating (I mean all the inductors, transmission lines,...; the power stage disipation is another thing) is just related to the average power.
But if your limit is electrical nature, DRM allows you just barely 1/3 of the average power, the reason is more than 3× PEP to average power ratio of the DRM (PEP is about 10×average) compare to AM (about 3.24x for a 80% modulation depth limit). And the electrical limit means a limit on the peak power (modulation peak), wha is the sme regardless of the modulation type.

Yup you will hear static from lightning on FM from time to time. 

I don't think an FM radio wouldn't pick up a lightning strike, unless its super close. I may have to try that.