Annual precipitation has increased in recent decades in northern and eastern areas  , and has decreased across the western part of the continent  , with considerable spatial variability within these regions . Elsewhere across North America there is limited evidence and low agreement on detection of observed trends in total precipitation and river flood hazards. The intensity and frequency of 1-day heavy precipitation events have very likely2 increased since the mid-20th Century across most of the USA  and in Mexico, but no detectable trend is reported in Canada . Recent flooding events along the mid- latitude Pacific Coast have been attributed to increasingly intense atmospheric river events , but there is low confidence in detecting trends in atmospheric river activity.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report