Is there a way to get an estimate of the concrete moisture before the building comes to service conditions?

While there is no way to calculate the exact Service Temperature as required in ASTM F2170 before all conditions have been met, the RH can be estimated.

Wagner has developed an estimation calculator found here: www.wagnermeters.com/RhEstimator/

To learn more about the estimator here: https://www.wagnermeters.com/rhtemp/