Is there any method to the madness regarding the times of balloons spawning? It seems like they mostly spawn from the East side I have noticed but the timing is quite random. Anyone have any info on this to share? Thanks
There's a someone on Reddit who posted a thread about the testing they did. From what I can tell, their conclusions seem pretty accurate.
Basically balloons are supposed to spawn whenever the time ends in 4 or 9. Yes, this means every 5 minutes. The balloon takes about 1 minute to float over from the edge of the map (over the ocean) to finally get into visible range from your island. During the day, they spawn from the east. During the night, they spawn from the west.
I personally have noticed that the time switch between day and night spawning seems to be at 6pm. I usually am fishing around that timeframe and so I can consistently see the change in spawns. I don't know when it changes to "day" spawns.