Leaving an FPGA outside

I've been following the Bitcoin scene for some time and have used my gaming computer to mine for bitcoins, but it's far from efficient and can only get a max of 220Mh/s. So I've ordered some BFL Singles and I'm planning on leaving them outside in the Southern California weather. I figured that since it's pretty much colder outside than inside my house during the night that the efficiency would go up. Now what I'm worried about is not the potential critters that could call the Singles their home, but the morning mist. I was thinking that since the Singles would be running pretty warm that the mist won't have enough time to condense on the PCB's components, and will actually help them carry out the heat away, but I'm not sure. Since the Singles will be warmer than the ambient temperature, condensation shouldn't occur. But what about water droplets that are in the air, such as in morning mists. How will it affect the life of the Singles?

Thoughts?

I may be overthinking this.