Scaling properties of raindrop size distributions as measured by a dense array of optical disdrometers

•Fractal dimension does not vary between instruments within a dense detector array.•Interstorm variability of fractal dimension can be substantial.•Fractal dimension consistently decreases monotonically with increasing drop size.•Fractal dimension is not well correlated to bulk rainfall variables. A dense network of optical disdrometers with 1min resolution was utilized through the winter months of 2013–2014 in South Carolina, USA, to explore the manner in which box-counting fractal dimension is related to drop size. Ten storms of a duration exceeding eight hours were selected for detailed analysis. It was discovered that detector-to-detector variation within each storm was negligible, though storm-to-storm variability could be substantial. The box-counting fractal dimension was found to decrease with increasing drop size, suggesting that large drops are more temporally clustered than small drops. Implications for raindrop sampling are discussed.