Climate of Chamela, Jalisco, and trends in the south coastal region of Mexico

Abstract

The warm, seasonally dry climate of Mexico's south coast is represented by data from the biological station at Chamela, Jalisco, and is compared with 26 other localities. The mean annual temperature was 24.9 °C; monthly mean maximums were equitable (29.1° to 32.0°) but minimums showed significant seasonal changes (14.8° to 22.9°). Local winds were strongest in the late dry season. Most cyclonic features moved parallel to the coast. Hurricanes made landfall much more frequently along some parts of the coast than others. The average annual precipitation was 748 mm, with a coefficient of variation of 16% for eight years. Rainfall was measurable on an average of 53 days per year, but the seven heaviest rains contributed over 50%.of the total; 80% of the total fell between 2 July and 4 November. Occasionally, there was substantial rain in December or January. For unsheltered lowland localities, rainfall increased with elevation, as did length of the wet season. Longer-term records (40 and more years) from four localities showed significant oscillations in precipitation that were correlated between sites.