We have essentially the same weather you do. I put feeders on a couple weeks back, and for the first few days, bees didn't do much with it. All of the hives have some honey still, but not a lot. When we had a week of rain, I put on a patty. The temps warmed up for a few days last week, and they all drained the feeders.
In our part of the world, and yours should be identical to us (only 70 miles across the water), spring is a bit of a balancing act. Once the bees get brooding, stores in the hive will vanish quickly. It really depends on the weather when the maples bloom, at least it does for us, where we have tons of maple trees. Dont know how much maple you have near the hives. The flow off the maples can be very heavy, and during april the bees can easily fill a super from it, if the weather is warm. If the weather is cold, they will miss the maples, and potentially starve because they got to much brood going, to early.
The way I see it, I stimulated the bees early, with feed and a patty. If the weather is warm during the maple bloom, it means they will have LOTS of bees in the colony to work on them. Conversly, if the weather turns cold and wet, it's up to me to make sure they dont starve along the way. I've got a green drone frame in all of the hives, and most of them have the brood nest right beside it. They filled that comb with syrup, and are storing pollen on the frame next to it, which is half brood as well. I saw the first maple buds yesterday, and my wife saw the first dandelion on Tuesday. Forecast for the next 4 days is mostly cloud and drizzle, so I'll be watching the hives. On Sunday or Monday I'll pop some lids, and see if they still have syrup in the drone comb. If not, I'll put more into the top feeders, which are empty right now.
I dont want my hives stuffed full of syrup right now, because we will throw supers on once the maples get going. If the hive is stuffed with syrup, there is a risk the bees move it all up into the super. At the same time, I dont want them running out of carbohydrates while they are building up early. We got two supers of maple honey last year from the two strongest hives, I'd love to get that again. Right now, the weather forecast is looking like we may get the chance too. 4 days of cloud and drizzle, then it changes to sunny and warm. If we get two weeks of sun, it'll be perfect for a strong flow off the maples, and the 5 acres of grass next door should explode into dandelions.
First year in our new location, so we are paying particular close attention to what is blooming where, and when. We were quite happy to find that a number of the neighbors here have hazelnut trees in the yard, the bees were all over them last week. A couple of the neighbors have commented that they haven't seen honeybees on the fruit trees for a few years, everybody hoping for a better than average fruit set now that the neighborhood has bees again.
