The seasonal distribution of rain helps the plateau people as well as the plateau plants. The transportation methods are primitive and the trails mere tracks that follow the natural lines of topography and drainage. Coca is widely distributed, likewise corn and barley which grow at higher elevations, and wool must be carried down to the markets from high-level pastures. In the season of rains the trails are excessively wet and slippery, the streams are often in flood and the rains frequent and prolonged. On the other hand the insignificant showers of the dry or non-growing season permit the various products to be exchanged over dry trails.
The activities of the plateau people have had a seasonal expression from early times. Inca chronology counted the beginning of the year from the middle of May, that is when the dry season was well started and it was inaugurated with the festivals of the Sun. With the exception of June when the people were entirely busied in the irrigation of their fields, each month had its appropriate feasts until January, during which month and February and March no feasts were held. April, the harvest month, marked the recommencement of ceremonial observances and a revival of social life.[39]
In Spanish times the ritualistic festivals, incorporated with fairs, followed the seasonal movement. Today progress in transportation has caused the decadence of many of the fairs but others still survive. Thus two of the most famous fairs of the last century, those of Vilque (province of Puno) and Yunguyo (province of Chucuito), were held at the end of May and the middle of August respectively. Copacavana, the famous shrine on the shores of Titicaca, still has a well-attended August fair and Huari, in the heart of the Bolivian plateau, has an Easter fair celebrated throughout the Andes.
Cochabamba
Cochabamba, Bolivia, lies 8,000 feet above sea level in a broad basin in the Eastern Andes. The Cerro de Tunari, on the northwest, has a snow and ice cover for part of the year. The tropical forests lie only a single long day’s journey to the northeast. Yet the basin is dry on account of an eastern front range that keeps out the rain-bearing trade winds. The Rio Grande has here cut a deep valley by a roundabout course from the mountains to the plains so that access to the region is over bordering elevations. The basin is chiefly of structural origin.
The weather records from Cochabamba are very important. I could obtain none but temperature data and they are complete for 1906 only. Data for 1882-85 were secured by von Boeck[40] and they have been quoted by Sievers and Hann. The mean annual temperature for 1906 was 61.9° F. (16.6° C.), a figure in close agreement with von Boeck’s mean of 60.8° F. (16° C.). The monthly means indicate a level of temperature favorable to agriculture. The basin is in fact the most fertile and highly cultivated area of its kind in Bolivia. Bananas, as well as many other tropical and subtropical plants, grow in the central plaza. The nights of midwinter are uncomfortably cool; and the days of midsummer are uncomfortably hot but otherwise the temperatures are delightful. The absolute extremes for 1906 were 81.5° F. (27.5° C.) on December 11, and 39.9° F. (4.4° C.) on July 15 and 16. The (uncorrected) readings of von Boeck give a greater range. High minima rather than high maxima characterize the summer. The curve for 1906 shows the maxima for June and July cut off strikingly by an abrupt drop of the temperature and indicates a rather close restriction of the depth of the season to these two months, which are also those of greatest diurnal range.
