CRACKEDRAILS 01 A cracked rail found along Metro rail at the Rosslyn station on Jan. 30, 2012. (WMATA)

UPDATE: The single-tracking has been resolved, according to Metro.

ORIGINAL POST: Another (frigid) day, another cracked rail for Metro.

The transit agency found a cracked rail on the outbound track at Bethesda, leading to single-tracking on the Red Line in the early afternoon.

The brutal cold was “likely a factor” in the rail breaking, Metro spokesman Dan Stessel told The Post’s Dana Hedgpeth.

Red Line trains are sharing a track between Friendship Heights and Medical Center, so riders should expect delays. The work should be finished and the single-tracking cleared in time for the afternoon and evening commute, according to Metro.

This follows a cracked rail that snarled Green Line travel Wednesday, which the transit agency also attributed to the drop in temperatures.

If you’re wondering: This problem isn’t unique to the Washington region. Transit systems in Boston and Chicago, among others, have had to endure delays stemming from cold-induced rail breaks.

Nor is this just a cold-weather issue. Hot temperatures lead to their own problems, as occurred last summer when the July heat was blamed for warping a section of Green Line track.

RELATED GRAPHIC: Why Metro tracks may crack