DATA to Insight

IPCC gridded climate data

The Intergovernmental Panel on Climate Change (IPCC) offers gridded 1/2 degree historical climate data for the world. I used R to format unprojected data and made animated gifs of temperature and precipitation for 1981-1990:

animated gif of temperature
animated gif of precip


  1. Warmer temperatures shift as the temperate hemispheres face the sun during their respective summers, although the tropics are always warm.
  2. The InterTropical Convergence Zone (ITCZ) shifts north and south, bringing a distinct dry season to Central Asia and equitorial Africa in the northern winter.


The data are text files in which each cell and month is a 5-byte string (e.g. -9999    9    9    9   10-9999-9999) with '-9999' representing NOT APPLICABLE (ocean or Antarctica).

All programming is in the R language. Most of the work went into constructing palettes. Both spatio-temporal time series are shown as 127 hues: Temperature on a 'blue-gray-red' palette, and precipitation on an 'orange-yellow-green' palette but strongly shifted to green to compensate for the skewness of the data.

The frames were assembled into an endless animated gif loop at a time-scale of 1 second = 1 month (e.g. 1:2,600,000).