DH went wandering around Costco and brought home a big bag of tulip bulbs. So I asked him, "Where were YOU planning on planting them?"
We currently have temps in the upper 80's here, so it really seems like it's too soon to plant them. Last bag of bulbs he brought home from Costco rotted in a week, so looking for suggestions?

Keep that man out of Costco! Seriously, though, I guess keep your bulbs in the coolest spot you can find, maybe a garage or well house? I usually wait until we've had a light frost to dig bulbs in, not necessarily out of wisdom but because there are so many other more pressing chores in the fall. Good luck.

Being in So.Cal., I can't even think about growing tulips, but could you put that bag in the fridge, until time to plant?

I plant daffodils as early as I can. I have a lot of failure with them when I plant later. Tulips and crocus do well planted later in the season for me. I have already planted 49 daffodils. Day temps have been in the 60-70's and night temps have been in the 50's. Many trees are dropping leaves but not changing colors other than yellow. I am expecting three bulb orders in Sept and Oct.

Not to worry. Tulip bulbs normally are extremely easy to store. Spread them out in a single layer in a well ventilated and dry, dark place. Keep away from fruit and other things that emits ethylene gas. Tulip bulbs are resistant to drying out, but high humidity is not good. Slightly below normal room temperature would be ideal at this time of year, but don't worry if it is a little warmer as this usually won't harm them. Throw away any that feels soft or lightweight. Plant when the soil temperature goes to 10℃/50℉ or earlier if they start to show signs of growth.

Ah, spreading them out in a single layer sounds like a very good idea. I do have a basement, but it seems a bit damp. Would burying them in a layer of fine wood chips be enough protection from the mild damp in my basement? This would only be for a month or so.

I store a lot of my own tulips over summer and I wouldn't personally feel comfortable burying them in fine wood chips in a damp basement. It sounds to me that the wood chips would impede airflow and I have a hard time seeing how a few wood chips would be able to absorb all the excessive moisture from the whole basement area. I occasionally store bulb that are susceptible to drying out in dry sand and this is the normal reason to why you would cover bulbs with something during storage. That said the bulbs might still be fine if you just need to store them for a month.

In my own experience two things can happen to tulip bulbs in storage. If it is too warm and dry for a long time the bud inside the bulb might dry out on very sensitive cultivars (all tulips are not the same!), but the bulb itself will grow just fine, it just wont bloom. Moisture on the other hand will make them start to show signs of growth early, which is not a disaster, but prevents long storage.

Moisture and high temperatures in combination would probably be the worst, but this isn't conditions I tried for my own bulbs.

The thing to remember here is that the tulip bulb is usually actually happier above ground than in it during the summer months. However if your soil is really dry and is likely to stay so for a while, then nothing prevents you from planting the bulbs early.

If uncertain I would divide the tulip bulbs and try storing them in a few different areas. Spread the risks and gain some knowledge for the future.

I compromised. I found some cardboard trays, spread them out and stored them in the coolest spot at the top of the stairs leading down into the basement. It has started getting much cooler the last few days, so I may be able to plant them out earlier than I thought.
Thanks so much for all the good advice!