The Sioux City and Pacific Railroad was extended to that point and train service began on April 1, 1883.

According to a news report, "The mountain and central time zones meet at the center of Main Street, so an hour separates the two curb lines."

According to the report, when clocks were required to be set back one hour for daylight saving time, Valentine's post office (which was in the central zone) split the difference and turned back its clock by half an hour.

[8] Valentine participates in an annual re-mailing program where thousands of pieces of mail flow into the local United States Post Office so that they can be re-mailed with a special Valentine's Day postmark and verse.

[10] In the Lakota language, Valentine is known as Oínažiŋ or Mnináȟaȟa Otȟúŋwahe, meaning "station stopping place" or "water and waterfall city".

[12] Valentine is immediately north of the Niobrara River, on the northern edge of the Sandhills physiographic region.

Merritt Reservoir, created by a dam on the Snake River, is about 50 km (31 mi) southwest of Valentine.

Designed by Josef Sorkin and built in 1932, the Bryan Bridge is made of steel and is listed on the National Register of Historic Places.

[13] A large red neon heart (a star during the Christmas season) is on the pine-covered Minnechaduza Creek canyon wall at the north end of Main Street.

With a humid continental climate (Köppen Dwa), Valentine experiences extremes of heat and cold annually; it is part of USDA Hardiness zone 4b.

[15] The average window for freezing temperatures is September 25 thru May 11,[15] allowing a growing season of 136 days.

[25] In 2011/2012, an independent feature film, The Aviation Cocktail, had its principal photography in Valentine.