This is a fearsome question to ask a beekeeper. If you ask three of them, you'll get four answers--or more! And each answer will tell you something different.
[This photo is from a month ago].
So far I've gleaned this advice:One beekeeper said it's okay to open the hive now for a quick peak (-1 degrees C) but no pulling frames. Go ahead and feed them (rim spacer with sugar water baggie on top bars) if I'm concerned if the bees have enough stores, otherwise it's a little bit early yet. A way to tell if they don't have enough food is if they're all at the top of the hive under the inner cover. If they're down in the frames, they're fine.
Another beekeeper agreed with feeding now repeating the advice above, but only if I was really concerned that they were starving because it is still a little bit early (southwestern Ontario - with snow still on the ground).
There's been emails about this too on the Yahoo groups beekeeper list.
Advice varied from, don't break the propolis seal by opening now as it'll let in cold drafts versus it's okay to crack the lid and drafts don't matter.
(Refer to paragraph two... Ask 3 beekeepers a question... yes I'm sure you understand it now).
Of course Where you are makes a huge difference, along with the temperatures in your area.
I'm concerned that our four hives went into winter on the light side and I want to start feeding as soon as possible.
These guidelines for opening a hive were posted on the Yahoo Beekeepers group and was subject to debate about whether it was good advice or not. (I remember reading these guidelines before so I know it came from a beekeeping book).
Below 30 degrees F
Open the hive only in emergency, such as to feed or remove chemicals. If feeding is necessary below 30 degrees F, we must use dry sugar so the feed won't freeze
Below 40 degrees F
Open the hive only in emergency, such as to feed or remove chemicals. Bees cannot get far from the warmth of the cluster at below 40 degrees F so feed must be placed directly above the cluster.
Below 50 degrees F
At 50 degrees F, the bees are loosely clustered. The hive can be opened but brood combs should NOT be removed. Side combs can be removed to look at brood combs, but must be replaced quickly to avoid letter the brood get chilled.
55 degrees F
Bees begin to fly at 55 degrees F, especially for cleansing flights. Honey bees will not defecate inside the hive unless they have Nosema – Honey Bee diarrhea. They will also begin flying to collect nectar and pollen if it is available. Hives can be opened, but care must be taken to avoid chilling the brood.
60 degrees F
Complete hive inspection can be made, but brood combs should be returned to the hive quickly.
70 degrees F
70 degrees F is warm enough to completely disassemble the hive and farms for a thorough inspection.
And just in case you're looking for lots of conflicting advice, here's a list of beekeeping newsgroups to keep you busy Yahoo.com.
What are you doing? Are you feeding yet?