Using Current Population Survey data, Vital and Health Statistics data, photoperiod data and temperature data, this article attempts to provide an interdisciplinary explanation of monthly (N = 243) variation in the dependent variable representing the birth rate (the rate of conceptions that become live births) for white women 20–24 years of age. Among the selected explanatory variables, four were found to play significant roles in accounting for the variation of the birth rate. They were rates of female absence from the labor market (nonparticipation plus unemployment), male employment rates, length-of-night variations and the days in the month of conception. Rainwater's concept of “validating activities” (1974) and recent quality of life research regarding domains serve as a basis for development of the concepts “compensatory validation” and “contextual compatibility”. Research and policy implications are discussed.