There’s a huge difference between swimming pool in summer and in winter in the area of Bloomington, Indiana, USA.
Bloomington is an area of irregular limestone terrain characterized by sinks, ravines, fissures, underground streams, sinking streams, springs and caves.  It is situated in the rolling hills of southern Indiana, resting on the intersection of the Norman Uplands and the Mitchell Plain.  The relatively varied topography of the city provides a sharp contrast to the flatter terrain more typical of other portions of Indiana. 
Just 50 miles (80 km) south of Indiana’s state capital, Indianapolis, lies the city of Bloomington, also known as “B-Town”.  With a population of over 71,000 residents, squeezed into just 19.9 square miles (52 km2), Bloomington is the seventh largest city in Indiana. 
The lowest temperature in Bloomington is 22 F in winter . Most of the land in Bloomington during Jan. and Feb. is covered with snow. The swimming pools in the community, are in the same situation – covered by snow. Can you find the hidden pool in the picture above named “Winter in Bloomington, IN”? It’s covered with heavy snow!
 Wikipedia: about Bloomington, Indiana, USA. Wikipedia. (Date of access: Sept. 25th 2010)
 “Weatherbase Historical Weather for Bloomington, Indiana, United Stated of America”, Weatherbase. 2009. Retrieved 2009-03-23.