In the current literature which covers nanofiber production it has typically been the polymer solution parameters and processing conditions which have been investigated. However in order to control the process further, thereby improving the reproducibility of the resulting fibre morphology, this report investigates the effect of the electrospinning environment by controlling air temperature and humidity. The system chosen here is the electrospinning of reproducible cellulose acetate nonwoven nanofiber mats using three different temperatures and relative humidities in a controlled environment cabinet to evaluate the effect on the resulting average nanofiber diameter by SEM and the corresponding thermal properties of the nanofibers by DSC. The polymer solution parameters and processing conditions remain fixed for the entire investigation.