WorldClim BIO Variables V1 (WORLDCLIM/V1/BIO)

WorldClim V1 Bioclim provides bioclimatic variables that are derived from
the monthly temperature and rainfall in order to generate more biologically
meaningful values.

The bioclimatic variables represent annual trends (e.g., mean annual
temperature, annual precipitation), seasonality (e.g., annual range in
temperature and precipitation), and extreme or limiting environmental
factors (e.g., temperature of the coldest and warmest month, and
precipitation of the wet and dry quarters).

The bands scheme follows that of ANUCLIM, except that for temperature
seasonality the standard deviation was used because a coefficient of
variation does not make sense with temperatures between -1 and 1.

WorldClim version 1 was developed by Robert J. Hijmans, Susan Cameron,
and Juan Parra, at the Museum of Vertebrate Zoology, University of
California, Berkeley, in collaboration with Peter Jones and Andrew Jarvis
(CIAT), and with Karen Richardson (Rainforest CRC).