The rainy weather has made pollen collecting a challenge for bees. The bees need the pollen to keep feeding their brood. No pollen and the brood can die and the colony moves backwards in colony strength.
This time of year right after the fruit bloom there can be a dearth of pollen available for around two to three weeks. Pollen patty's are needed now to keep the brood well fed and the colony strength up before the main nectar flow hits.
When checking the bees this time of year a beekeeper has to make sure there are enough food stores to get to the honey flow. Usually I pick up a brood box and judge by weight if they have enough honey. A heavy box means they are good for a week, if it is light weight I feed.