hard to predict the interest rate short term

But I think it should fluctuate from 6% to 6.625%(no cost)
for 30 yr fixed.

For Tuesday, the rate is already at 6.625%, it's high compared to the interest rates in the past 6-7 years.
But we can not say that interest can not go lower.

So if want to refinance and your property value is stable, you can wait; for the purchase, you can lock or wait since you will refinance later anyway.