Most of the Pacific zone is ''tierra caliente'', the "hot land" of tropical Spanish America at elevations under . Temperatures remain virtually constant throughout the year, with highs ranging between . After a dry season lasting from November to April, rains begin in May and continue to October, giving the Pacific lowlands  of precipitation. Good soils and a favourable climate combine to make western Nicaragua the country's economic and demographic centre. The southwestern shore of Lake Nicaragua lies within  of the Pacific Ocean. Thus the lake and the San Juan River were often proposed in the 19th century as the longest part of a canal route across the Central American isthmus. Canal proposals were periodically revived in the 20th and 21st centuries. Roughly a century after the opening of the Panama Canal, the prospect of a Nicaraguan ecocanal remains a topic of interest.