This paper presents recent experimental results from the obsidian hydration dating research programme conducted at the Centre for Archaeological Research (CAR), Auckland University. Two elements of the essential hydration rate component are examined. First, the influence of potentially significant environmental variables other than ambient temperature is explored. Our results demonstrate that environmental variables other than temperature may have a significant influence on hydration rate, though for many archaeological situations their influence is insignificant. Second, an alternative approach to estimating the exponential mean temperatures necessary for dating is presented. It is based on modelling the soil surface energy balance. A comparison with other prediction methods shows it to be a preferable approach. Finally, the results of a blind dating applications are presented. These show that the dating method can produce results which are both sensible and useful.