As long as your soil isn't frozen or water logged, plant them now. We're about to have more nights about freezing than not in most of zone 7. You can keep planting radishes seeds every 7-10 days or so until late April-early May. They won't germinate well when the ground gets too warm either and the plants will bolt quickly and not form edible roots when the temps are warm.

Radishes can survive light frosts and cool weather. Radishes will not grow good edible roots when hot. You can basically plant Radishes when winter is over and plants start growing in early spring. Probably plant seeds late March to early May in your area. You can probably plant seeds again in September when nights get cool again.

Actually, the forecast is for lows below freezing for 4 out of the next 5 nights. Maybe by end of next week I'll be able to plant.

Radishes can take below 32 degrees, and doesn't bother the seeds at all. If the soil is too soggy to work, and cool, maybe not worth the bother since the seeds will not grow very fast. Really just a judgement call. Seeds are cheap, you can always plant an early small planting and see what happens.

@hbibna zawali was there supposed to be a link in your message?

But don't grow radish transplants. Just direct seed them. Use row cover or similar if you want to rush the season.

You could,ve planted earlier. Or right now.

The only question is, will the seeds germinate? At cooler tempeeatures it will take longer. But once they germinate, frost is not going to kill them . I had turnips all winter with lows going down to 22F. Few times. Radish and turnips are close relatives.