The weather here in the northeast (near NYC anyway) has been so bad this spring that we rarely see the sun anymore, the days are cold (I can't find reliable statistics on May's tempearatures, but I would bet it was ~10oF lower than average) and often rainy.
I don't have enough experience to tell how this affects the bees, but I can't imagine them loving it too much. For one thing, I notice mold on the inside of the outer cover (which I did not see last year), etc.
I have kept a small feeder going throughout this first month since I got my bees and, although they have used very little of it, I think they use some of it when they can't fly because of rain.
Any thoughts anyone?