Yellowing tops aren't normal for onions at this time of year. Depending on how long the soaker is going, every other day sounds like a bit too much water for the onions at this time unless your soil drains very quickly. It could also be fertilizer burn on the roots as they grow but I'd guess water first.

I'm in about the same zone as you (and definitely dry) and I'm watering once a week for 5-10 minutes with a hoze end wand. I planted plants around 4/10 and it took the first couple of weeks for them to grow roots and now they are greening and starting to produce the first new growth. Try not watering until Friday at least and see if they start to recover.

Thanks Makalu. The last 2 days of rain probably didn't help the over-watering situation. Hopefully, it will dry out this weekend. Should I start the high nitrogen fertilizer soon?
John

If your soil is well amended in addition to the fertilizer that you applied at planting time, you may not need the high nitrogen stuff. If you're going to apply it, any time from now until the middle of June is good for our area ... much past that and I've found that the onions don't seem to size up as much and don't keep as well.

Thanks for the good advise, Makalu. It looks like my onions have turned the corner and are starting to green up and grow.
John