What is too cold for feeding/foraging?

[Grid]

My hives are a little light on stores, and I am a little late getting the syrup on - I put 2:1 on the hives on Saturday.  We are seeing daytime highs of around 15C (60F) and lows around 7C (45F).  There are still Asters and Goldenrod in bloom.

When is it too cold for foraging?  When is it too cold for them to take syrup?

Thanks!
Grid.

[Grid]

Wikipedia gives half of the answer.

The minimum temperature for active honeybee foraging is approximately 55 °F (13 °C). Full foraging activity is not achieved until the temperature rises to 66 °F (19 °C). There are small differences in the races of the Western honey bees at what temperature they will start foraging.

Google provides the other half:

If outside temperatures are lower than 5C (40 F) the sugar syrup might get too cold and the bees will not go to it until it warms up.

Suppose I should have googled before posting.  Hopefully having the syrup above the hive over the inner cover will help keep it warm.

[AliciaH]

Gotta love Wikipedia! :)  What kind of feeders are you using?

Most of my feeders are top feeders.  I know it's too cold when they stop coming up to get the syrup.  If I have a hive I'm concerned about, I'll switch the top feeder for a frame feeder so they don't have to leave the deep to get to the syrup.  That usually works for awhile.

[Grid]

I'm using mason jars over the hole in the inner cover.  They're taking it slow right now, but I _think_ they're taking it.

[Tommyt]

I think I saw(you tube) a Guy in Me. with heated syrup  and I think Hive heater

[Grid]

Well today is a nice 19C (66F), so hopefully the bees are getting a little of both done (syrup and nectar).  A few more days like this could help a lot.

Come on bees!!!  :)