24th Pacific Science Congress (PSC-24)

Theory suggests that high-intensity, short-duration rainfall events should become more intense under enhanced greenhouse warming with an increasing tendency somewhat higher than 7% per degree Celsius. Here we present the production and analysis of a dataset of hourly rainfall records from 56 locations across Aotearoa New Zealand covering the 1986-2024 period, as well as from 17 locations covering the 1965-2024 period. We compare variability and trends across the locations in the highest and fifth-highest annual values, for one-hour and multi-hour durations. We finish with an assessment of the contributions to the variability and trends using 2800 years of 12km resolution detection and attribution simulations.