For each of December and June, one map shows solar radiation and its variability on a horizontal surface, a second shows solar radiation on inclined surfaces. Data primarily for period 1956-1978. For each of April and October, one map shows solar radiation and its variability on a horizontal surface, a second shows solar radiation on inclined surfaces. Data primarily for period 1956-1978. Maps also contain time zone boundaries.
Graph shows length of day throughout the year.
Climatic data for 1941-1970 used for both aspects. Thermal Efficiency Regions . Climatic data for 1941-1970 used for both aspects. Data is from the recording period 1941-1970. Data is from the recording period 1951-1980.