Despite increasing concerns about the vulnerability of species’ populations to climate change, there has been little overall synthesis of how individual population responses to variation in climate differ between taxa, with trophic level or geographically. To address this, we extracted data from 132 long-term (≥20 years) studies of population responses to temperature and precipitation covering 236 animal and plant species across terrestrial and freshwater habitats. Temperature tended to have a greater overall impact on populations than precipitation, although the effects of increased precipitation varied strongly with latitude, being most positive at low latitudes. Population responses to increased temperature were generally positive, but did not vary significantly with latitude. Studies reporting significant climatic trends through time tended to show more negative effects of temperature and more positive effects of precipitation upon populations than other studies. Our results identify likely geographical differences in the effects of climate change on populations and communities. Most studies of climate change impacts on biodiversity have focussed on temperature and are from middle to high northern latitudes; our results suggest their findings may be less applicable to low latitudes, where most species occur and where variation in precipitation under climate change may be more important in determining demographic responses