In 2003, Forster and Solomon (Observations of a weekend effect in diurnal temperature range, PNAS, [ http://www.pnas.org/content/100/20/11225.full ]) reported: we find evidence of a weekly cycle in diurnal temperature range (DTR) for many stations in the United States, Mexico, Japan, and China.
The total cost to have a concrete retaining wall installed will be a combination of material and labor prices. For a basic wall you can expect to pay between $30 and $40 per square foot.
In general, a typical landscape curbing job requires between 180 and 300 square feet of concrete. The average cost of concrete depends on its composition: pre-formed, individual blocks or poured. The cost of standard, pre-formed concrete blocks will range from approximately $2 to $3 per square foot. The cost of standard, pre-formed blocks for a project requiring 200 square feet of landscape curbing would total about $400 to $600.