I plan on customizing Morrowind.ini weather settings.
I am not sure how to do this apart from editing the file and testing over and over.
I do have a Tempus Fugit ring (not sure which mod gave me that) and can rest normally with T key to help control the time of day.

Are there any console commands or mods for cheating and setting the time of day or weather? Or for changing lighting inside the game?

Thanks!

My mod "A Forgotten Heresy" will allow you to control the weather.
It works everywhere on Vvardenfell and Solsthiem.
It also works in Mournhold, but only after completion of the Tribunal Main Quest, for lore-correctness reasons.

It is controlled using a special spellbook and scripted toggle spells.
Also included is a "cheat" version that makes the spells cost zero magicka, and makes the book itself much easier to get.

My mod can be found here: http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=8006
Enjoy!

You can change the weather with the console:
ChangeWeather, [Region], [Type]
Region = Region name to change the weather in. (obviously the Region you're currently in)
Type = The type of weather to change to.
0 = Clear
1 = Cloudy
2 = Foggy
3 = Overcast
4 = Rain
5 = Thunder
6 = Ash
7 = Blight
8 = Snow (Bloodmoon required)
9 = Blizzard (Bloodmoon required)

After changing the weather, I do believe you have to change cells at least once, or wait 12 hours, before they happen.
I do believe there are weather changing mods as well, so you don;t have to use the console. Easy to find on PES, I'm sure.

For your ini, I highly recommend checking out the ini changes that Vurt suggests with http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=8085. (it saves you the trouble of spending many days trying to figure out the tweaks yourself)

You cannot alter the Lighting settings from within the game.

To change the time of day instantly, use set gamehour. Example:

6am
set gamehour to 6

12:30pm
set gamehour to 12.5