Consistent large-scale response of hourly extreme precipitation to temperature variation

Hourly precipitation extremes can intensify with temperature at higher rates than expected from thermodynamic increases explained by the Clausius-Clapeyron (CC) relationship (~6.5%/K), but local scaling with surface air temperature is highly variable. Here we use daily dewpoint temperature, a direct proxy of absolute humidity, to estimate at-gauge local scaling across six macro-regions for a global dataset of over 7000 hourly precipitation gauges. We find scaling rates from CC to 2xCC at more than 60% of gauges, peaking in the tropics at a median rate of ~1.5CC. Moreover, regional scaling rates show surprisingly universal behaviour at around CC, with higher scaling in Europe. Importantly for impacts, hourly scaling is persistently higher than scaling for daily extreme precipitation. Our results indicate greater consistency in global scaling than previous work, usually at or above CC, with positive scaling in the (sub)tropics. This demonstrates the relevance of dewpoint temperature scaling to understanding future changes.