Here's a picture of the plants..

Here is a link that might be useful:

I'd be leery about putting them out for the first time at quite so cold a temperature. Can you start on the weekend a little later in the day, so that by Monday morning they've had some gradual exposure to the outdoors? I don't leave mine out for more than a couple of hours the first day or two anyway. And I like starting on the weekend so I can take them in if the weather takes a turn for the worst.

This is the third day I've put them outside.. the first two days were in the evening as soon as I got home from work for a few hours. I'm just curious if leaving them outdoors under shade for a few days would be beneficial given the lower temperatures.

I'd keep them in a sheltered spot next to the house. It's bound to be a few degrees warmer there. I tend to be cautious. That said, it's a nasty, chilly (high of maybe 59 degrees), drizzily day here, and mine are on the porch. Hoping for some milder weather at the end of the week so I can leave them out overnight.

Ok that's what I'm doing.. they're sitting under may porch next to the house. The closet door they're against is actually the water heater closet so it's probably radiating a bit more heat and creating a micro climate.

I'll keep putting them there for the first week and move them out under in the full sun for a couple hours each afternoon for the next couple weeks. Assuming there's sun.. this week looks pretty wet after friday so I'll probably just keep putting them out on the patio out of the direct rain.

The down side to the northwest is that we are not the ideal tomato climate.