I often hear that it's better to requeen in the fall than in the spring. For these reasons:
Lest disruption in Colony
What other plans are out there?
Requeening is difficult in the fall if there is no honey flow on the field. August in Finland is difficult time.
It must be egg laying queen during August that it makes over wintering bees.
In the begining of September we take honey from hives away and we give 20 kg sugar per hive. When taking sugar liguid it is easy and safe to give new queen to the colony.
There is narrow time when we get queens in Finland. We can buy in May queens from southern countries but they are not good in our climate.
***Better Queens - local race, yes
***Better Acceptance- oh no
***Lest disruption in Colony - ???
Not early but the in July requeening is better. If new bees are angry or week against foul brood, you have time to requeen it again.