It was 53°f here this morning, Jack. I could hardly believe it! Yep, I left some tomatoes out and, if'n I've got time, they will be planted in the garden, tomorrow.
It hasn't been the cold that slowed the harding-off. There has been some wind but it's the direct sunlight. I've only got the one, small sweet spot in the backyard. Every place else is either 100% sun or 100% shade. Where they will go in the garden is 100% sun (& too much wind). The late May weather outdoors has been kind, tho ...
The hoop houses tend towards exactly the same temperature as outdoors, by morning. I wish it wasn't true but that's how it goes. If it's 35° by 7am, it will be within a couple degrees of that in either hoop house if I haven't put a heater in there. My alternative is to crowd things in the greenhouse with its furnace and thermostat. Luckily, it's been a couple of weeks since I've had to be concerned about any of that.
Steve