Forced Nest Migrations

In Pokémon GO, a "forced migration" refers to an unusual shift in nest locations, occurring outside the regular schedule.

This typically happens in conjunction with in-game events, especially those introducing new Pokemon. Although, not always.

Under normal circumstances, nest rotations follow a bi-weekly pattern, changing every second Wednesday at 5 PM Pacific Time.

However, during a forced migration, these nests undergo an unexpected rotation or "migration", deviating from their usual bi-weekly cycle.

Pre-migration nest reports will be marked as "expired", deviating from their usual update schedule.

This means that the information is no longer reliable, as the Pokémon species in these nests have likely changed.

For a detailed log of Forced Migrations, see here:

No, a forced migration in Pokémon GO doesn't alter the timing of the usual nesting cycle. It merely interrupts the current cycle.

So, if a regular nest rotation was scheduled to occur in 7 days, it will proceed as planned, happening in 7 days despite the forced migration.

This means that the standard bi-weekly rotation of nests remains consistent, regardless of any mid-cycle disruptions caused by forced migrations.

Of course, Trainer!

Let's say Shroomish was nesting at a local park for 8 days.
On the 8th day, a special in-game event is launched, introducing a variety of new Pokémon. As a result of this event, a forced migration occurs.
Consequently, the Shroomish nest at the park changes - let's say it now becomes a Growlithe nest.
This new Growlithe nest will remain for the rest of the nesting cycle, which in this case is 6 more days (since nesting cycles last for 14 days).
After these 6 days, the nests will rotate again following the regular schedule.
Unless there's another special event, the nesting schedule will continue to follow its typical bi-weekly rhythm.