I'm not sure any of these responses has answered the question.
Our procedures call for a post-calibration on the same day as the measurement.
The measurer needs to perform the required post-calibration rides. He can take a chance by waiting to see if the temperature recovers and the course dries, but that's exactly what he'd be doing. If the conditions don't improve, he needs to recalibarate under the best conditions available to him.
If the temperature drops and the constant changes in a way that makes the measured course distance short, then he needs to go back to the course and lengthen it. The course may not be as accurate as we'd like- but at least the course won't be short.
I'm a strong proponent of frequent recalibration, but unless you lay a new calibration course in the vicinity of every course you measure (or are measuring in the vicinity of a calibration course you've previously set) you can't always do that- at least not efficiently.
Sometimes feces occurs. This is one of those times.