temperatures vary from bin to bin their is no way of telling just by guessing you need to check the temp yourself using a soil thermometer.

if the room temp is 41 degrees the bin temp should be less that is a fact. are you even sure your worms can handle less then 41? i don't think red wigglers can if this is the case you will need to put them somewhere warmer or get a heating mat and put that in

I think I'll try finding a thermometer i can use especially for the bin. Any suggestions?

Right now, the roomis 62 degrees. I've heard ideal temps are between about 50 and 80 F.

The worm bin is generally warmer than outside temp. It has insulation and built-in heater. Yes, heater. The decaying organic matter (food) will heat the worm bin up. The heat amount is based on the amount and type of food you added recently.

The worms can survive as long as their worm bin doesn't freeze, in 32 f (0 c). But their activity will be slowed as they're sort of hiberating, and maybe they'll clump together to keep themselves warm, next to decaying food. The result is they'll eat less.

If you'd like to keep your worms warm, you can add insulations. Some people wrap their bin with sheets, tarps, straws, as long as it doesn't impede air flow and drainage.

You can also try to keep it warm by feeding specific food that's known to heat the bin up quickly, such as grains and rice. Just be careful and don't bake your worms by accident.

Or you can bring it indoors.

If you have a thermometer somewhere, I'm sure it'll help to settle any uncertainty you may have.

Thank you Aindra, that's a relief. I thought the bin would naturally be warmer than the outside temps, thanks for clarifying. I'll make sure to monitor the temperatures. Can you let me know at what temperature they begin to slow down? Is it at 32 degrees?

No. The ideal temperature is 55-77 f (12-25 c), from what I've read around here. (Note: They vary. Some says 60-80, some says 50-80.) It means the red wigglers will be most active. Further you go outside the range, they get slower.

Below 32 f (0 c), and above 90-95 f (32-35 c) can kill the worms so try to avoid those.

Personally for me, I'm worried when it's hot, not cold. Because when it gets hot, the decaying food and insulation aggravate it. It's harder to keep it cool, than keep it warm.

Thanks so much for that information. I brought them inside to warm them up and keep them productive (and alive).

Aindra's comments are insightful.

re thermometers, any soil thermometer will work. The "Taylor Soil Testing Thermometer, 4" Stem, -20 to 180 Degrees F" on Amazon is an example.

Because decomposition releases heat, active compost will always be warmer than the ambient temperature. How much warmer depends on what you put in recently. Dump in a quart of potato peels and it will get alarmingly hot; cardboard and coffee grounds, not so much. My experience with stackable bins is that the bin interior is generally about ten degrees fahrenheit above ambient temperature.

Further, as Aindra points out, the bin has enough thermal mass that its interior temperature will be affected by the average ambient temperature, not by night-time dips.

If the outdoor temperature stayed below freezing, day and night, for a week, I might think about bringing the worms inside. But a night-time dip to 40 is absolutely no problem, and getting a thermometer will reassure you of that.

This is what I use, works great and I've had it now for about 3 years.

Here is a link that might be useful: Thermometer

Forgot to mention that you can add more food to keep the bin warm in the winter.
Normally I keep the center around 85 degrees. Midway out, it's around 74 or so and on the periphery around 55-60.
The worms just find the temp they like best and move to there.
I've had it get as high as 108 in the center, but the periphery was still cool enough. I wouldn't recommend that, however. :)