Temporary table in pgAdmin

Postgres creates a temporary schema for temporary tables named "pg_temp_#", you can see it with psql...

create temp table mytemptable(name varchar);

select c.relname
from pg_namespace n
  join pg_class   c on n.oid=c.relnamespace
where n.nspname='pg_temp_1';

You can list your schemas executing "\dn" in psql.

Hope that helps.

Temporary tables live in temporary schemas pg_temp_{№} that hidden by default in pgAdmin UI.

In pgAdmin(pgAdmin4 at least) you can open preferences pane and switch on this setting:

Display->Show system objects? to True

This will show hidden schemas with your created temp tables.

PS After changing preference refresh schema tree