Shade audits implemented for the assessment of solar ultraviolet (UV) protection within parks and playgrounds require standardisation in order to make clear and objective comparisons of the whole environment. Children utilising a park or playground may use a recreational space only at a certain time of day, they may only utilise a specific area of the playground and will likely experience sunburn if exposed to solar radiation for an extended period of time. The level of protection provided within a playground or outdoor parkland will change during the season, time of day and year. Subsequently, spot measurements of the Ultraviolet Protection Factor (UPF) taken using handheld radiometers underneath a purpose-built shade structure or playground shade sail may not necessarily define the effectiveness of protection afforded within the whole defined space, nor give an accurate indication of the level of protection provided over a specified time interval due to the changing position and elevation of the sun. The Playground Shade Index (PSI) is introduced as a measure of the average UV exposure received over a defined playground region for a defined interval of time expressed relative to the available ambient UV exposure that would be received in that same period. The utility of the PSI as an objective comparative metric for assessing UV protection is presented for a range of conditions, seasons and different playgrounds located in proximity to the University of Southern Queensland solar radiation base-station.