I'm having a hard time following the spawn times of red & blue buffs. It seems nearly random to me. One time I clock them at 3:39, the next over 4 minutes, and once I even saw them spawn while I still had the original buff on (?).

Are the spawn times random? Because if they are it'll help me convince myself i'm not crazy. I'm **** certain I had the original lizard buff on when the 2nd one spawned.

Anyway, what're the spawn times for red & blue, if they're not random?

They are not random.
All jungle creeps have spawn time.

When you kill one camp of jungle creeps a clock will start ticking. Once it reache a certain number it will make the creeps spawn agian.
The buff creeps first spawn at 1:55 and depeing on when you kill them there will be different numbers when it will spawn.

So that it spawns the second time different time each game simply depends on the simpel fact that it took a shorter / longer time to kill it.

Cheers
Sawy-Janna player

Ill give u some spawn times

Blue/red buff = 5 minutes, usualy comes back around 7.10 if u start at blue, so watch your times, you dont want it to get stolen.) you can also ward their buffs to try and steal theirs. or setup a gank if u know the timers.
Dragon = 6 minutes.
Baron = 7 minutes,
little creept (not sure, think it was 1.30 minutes)

The thing with the original buff might be that u killed the enemy jungler, if u kill him, you will get his buffs and the timer will just reset. so you will have another full buff duration.

http://leagueoflegends.wikia.com/wiki/Summoner%27s_Rift

have fun

the mini map icons reappear when they respawn, so no real need to clock them

wolves/wraiths/golems= 1:40 (100secs)
Blue/red= 5:00
Dragon=6:00
Baron= 7:00

Wave spawn: Every 1:40(100secs)
Every 3 wave spawns, 1 tank creep

And THAT people has gold ranking.
Proving once again that people with a gold badge have no reason to be cocky