Although I live in temperate SF Bay area, there are at least 2 worm sellers nearby (Antioch & San Jose) who successfully raise worms in garages that reach over 100F in the summer. Basically the bedding insulates the worms from the high air temps. It depends a little on the type of worm bin you have. In general a well-established bin with substantial bulk should work fine in high air temps. You just need to make sure absolutely no sunlight hits the bin.

An in-ground wormery (see link below) will also work. Simply dumping the worms in the soil won't work as well. The worms need organic matter & the accompanying ecosystem of microbes to feed off and plain garden soil may not have enough of that. You will want to consider protection against rodents or other predators (mostly birds). Again, it's probably best to position the wormery out of direct sun.

One idea I've been considering is embedding an 18 gal. tote in the ground. I was going to drill extra holes in the bottom for drainage. Of course this works if your soil has good drainage.

Good luck.

Andrew

Here is a link that might be useful: in-ground wormery

You Might be able to save some worms but instead I would do this. Find some shade, preferably all day shade. Then get a deep plastic container and bury it all most all the way up to the lid. Drill some holes in the lid and in the bottom of the bin if your bad about having too much moisture in the bin. Then lay about 4 or 5 layers of cardboard around the bin to insulate the soil. Keep the soil moist under the cardboard if that is possible. I think this would work to keep the bin cool enough for the worms to survive, if not flourish. Steve

Any of the above ideas should work. Sounds like you are in the Phoenix or Tucson area, I am down in Cochise County and kept my worms in 18 gal totes all summer last year with no problems. Worms are pretty durable.

Tracy .... That in-ground wormery looks great, but if you don't have time to do that or the other ideas, may I suggest that you make up your small bin, which I assume you will keep inside the cooler house.... and put an ad on craigslist and either sell or give away the extra worms.

You could put in frozen water bottles wrapped in layers of newspaper to reduce the temp. in the bins.
That worked well for me last summer.

IMHO a tote with adequate ventilation would be preferred over a flow-thru if over-heating was an issue. Flow-thru systems have a tendency to be much drier than totes, and I would think dry heat would be harder on worms.
It may be time to consider a bigger system. Although your concern is to keep the worms you have now alive, worms do much better in bigger systems (in fact, the bigger, the better). A bigger system allows you to insulate from excessive heat with light, fluffy bedding like straw and overfeeding is no longer a problem, they simply move to an area they are comfortable in.

My worms got through the Australian summer just fine, I put some carpet underfelt on top of the open bin and kept it damp, evaporation then kept the bins cool.

I live in the Queen Creek area and started a new garden 1 year ago. I use all organic ammedments and do "in row" composting and yet I have no worms. I tried adding a container of fishing worms that I bought at the WalMart but they soon left even though I had plenty of "food" for them. Help! What am I doing wrong?

You probably got NightCrawlers - they like to do a runner.