After the ground thaws and more importantly dries out so you won't be planting in cold AND wet soil. 40 degree soil temperature should be fine for planting out. Air temps are not that important for the first 2-3 weeks until they start sprouting top growth, but any leaf growth above ground after that point will get killed back by a freeze, but this only sets them back a little.

Agree, wet soil must be avoided, also, after cutting, let the cut side "scab" for a few days to heal before planting.

And if you've got leaf growth and freeze threatens, you can throw something over them overnight.

Phenology is the study of cycles in nature used to determine when to plant and harvest. For example, someone who follows this theory would plant peas when forsythia blooms and potatoes when dandelions bloom. Farmers' almanacs typically use these kinds of measures, and I've found they generally work for me. In addition, the key with potatoes in areas with hot summers is to get them in early enough so they begin to bulk up before the heat arrives. That takes 6-10 weeks depending on variety. But if you put them in too early, they take much longer to start growing and you risk them rotting in cold wet soil and/or having their first sprouts killed by frost. That may not kill them, but it can weaken them and reduce your yield. I've found that planting in early to mid-April works in my area.

I am looking at putting in one oft movable tunnels with potatoes this week.

I am tempted to plant out early here too Jay. Looks like our weather is trending up starting this weekend but not much rain predicted any time soon. I am still waiting for Planters Seed and Spice to get their shipment of seed potatoes and Dixondale onions in. They usually have them the first week of March with the exception of the fingerlings that they get in around St Patty's day.