Environmental fluctuations are ubiquitous drivers of ecological and evolutionary dynamics in natural ecosystems. Predictable seasonal fluctuations favour life histories that capitalise on optimal time windows, whereas bet-hedging strategies are favoured under unpredictable environments. This life-history trade-off between maximizing gains and minimizing risks in response to distinct levels of seasonality and predictability has the potential to underpin global patterns of temporal diversity. However, this assumption has only been tested at a local scale. Here we combined global freshwater community time series to disentangle the role of structured environmental variability on determining temporal community dynamics. We used signal processing techniques and information theory to characterize locations based on their degree of environmental seasonality and predictability and quantified community dynamics using temporal beta-diversity and stability metrics. Preliminary results indicate that species asynchrony and within-year beta diversity increased with seasonality and predictability due to higher seasonal turnover. This suggests that the distribution of structured environmental fluctuations is indeed a key driver of temporal community dynamics. Our understanding of the effect of environmental variability on community dynamics is incomplete without incorporating its temporal structure. In this regard, more theory is needed if we are to predict the impact of altered patterns of environmental fluctuations on freshwater biodiversity.