The all bees don't mate in the colony. The worker bee's are females and they were unfertilized and don't mate with the male.
Only queen can mate with male. Because queen is the fertile and able to lay eggs after mating. Everyone wants to know what is the time and in which month bees mate? The queen bee mate in the season of flora and the blooming time. The blooming time of the flowers will comes normally just after the rainy seasons.
The all seasons are not good to mate queen bee. In the dearth periods when the food is not available in the outside the males will be killed by the other worker bee's. That's why if the drones (the male) is not available in colony the queen don't mate. For mating the male is required in the colony and in the dearth period the male not available. When the season of flowers start and nectar and pollen is available in the outside and worker bee's regularly bring it in the colony.
Normally the queen mating in any month this is depend on food availability. No month is fix to mate for queen it depending on the season if the migration is perfectly done in the place you would find in other areas where the food source for bee's are available then any time queen must be mate.
The main thing is to know is the queen only mate in the beginning of her life normally one week to ten days after hatching from cell. Queen can mate multiple times and once she mate in the sky during flight she can lay eggs whole life till she die.
If you want to know the month of mating of the queen you must know the details of that area. You can meet the bee keeper in the area you are looking for. The bee keeper only tells you the exact month of the bee's(Queen Bee) In northern India in the month of October to March is the time to queen mating.
The link bellow can help you to know about the bee's behaviors
Italian Bee Apis Mellifera