It's going to be bitterly cold this weekend, which is good news for those of us who hope our exes die of frostbite in time for Valentine's Day. It is bad news, however, for anyone who needs to get from Point A to Point B and back, especially since the trains are doing their usual whackadoodle weekend dance. Here's what's on tap this weekend:

2 trains will run in two sections: between Flatbush Av-Brooklyn College and E 180 St, and then via the 5 to/from Eastchester-Dyre Av, and then between E 180 St and Wakefield-241 St, with that change in effect from 3:45 a.m. Saturday to 10 p.m. Monday. E 180 St-bound 2 trains run express from Wakefield-241 St to E 180 St during that period.

3 trains will not run in either direction between Harlem-148 St and 96 St from 11:45 p.m. Friday to 5 a.m. Tuesday.

Woodlawn-bound 4 trains run express from Grand Central-42 St to 125 St from 11:45 a.m. Friday to 7:30 a.m. Monday, and again from 11:45 p.m. Monday to 5 a.m. Tuesday.

5 trains will run every 20 minutes between Eastchester-Dyre Av and Bowling Green from 6 a.m. to 11:30 p.m. Saturday, from 8 a.m. to 11:30 p.m. Sunday, and again from 6 a.m. to 11:30 p.m. on Monday. 2 trains will replace 5 shuttle service between Eastchester-Dyre Av and E 180 St from 3:45 a.m. to 7:30 a.m. on Saturday and again from 11:30 p.m. Saturday to 9:30 a.m. Monday.

Pelham Bay Park-bound 6 trains will make express stops from Grand Central-42 St to 125 St from 11:45 p.m. Friday to 5 a.m. Tuesday. Brooklyn Bridge-City Hall bound 6 trains will run express from Parkchester to 3 Av-138 St during that period.

Hudson Yards-bound 7 trains run express from Mets-Willets Point to Queensboro Plaza from 6:45 a.m. to 10 p.m. on Saturday. On that same track, trains run express from Mets-Willets Point to 74 St-Broadway from 3:45 a.m. Sunday to 10 p.m. Monday.

A trains will not run in either direction between Euclid Av and Lefferts Blvd from 12:01 a.m. Saturday to 5 a.m. Tuesday. During that period, A trains will run in two sections: between Rockaway Blvd and Far Rockaway, every 20 minutes, and between Inwood-207 St and Euclid Av. Brooklyn-bound trains will run express from 145 St to Canal St from 11:45 p.m. Friday to 6:30 a.m. Monday, and again from 11:45 p.m. Monday to 5 a.m. Tuesday.

Brooklyn-bound C trains make express stops from 145 St to Canal St from 6:30 a.m. to 11 p.m. Saturday to Monday.

D trains will run local between 36 St and DeKalb Av from 12:01 a.m. Saturday to 5 a.m. Tuesday.

Jamaica Center-Parsons/Archer bound E trains run express from Roosevelt Av to Forest Hills-71 Av from 12:15 a.m. Saturday to 7 a.m. Monday, and again from 12:15 a.m. to 5 a.m. Tuesday.

Coney Island-Stillwell Av bound F trains will skip 169 St from 11:45 p.m. Friday to 5 a.m. Tuesday. Trains on that line will reroute along the E line from Roosevelt Av to W 4 St-Wash Sq during that time.

J trains will not run in either direction between Hewes St and Broad St from 11:30 p.m. Friday to 5 a.m. Tuesday.

M trains will not run between Myrtle Av and Essex St in either direction from 6 a.m. to 12 midnight on Saturday to Monday.

All N trains run local from 59 St in Brooklyn to DeKalb Av from 12:01 a.m. Saturday to 5 a.m. Tuesday.

Q trains will not run in either direction between 57 St-7 Av and Kings Hwy from 11:30 p.m. Friday to 5 a.m. Tuesday. [The MTA sent out a revised schedule eliminating this change on 2/12]

R service is extended to Jamaica-179 St from 6:30 a.m. to midnight Saturday to Monday. Jamaica-179 St bound R trains run express from Roosevelt Av to 71 Av from 6 a.m. to 7 a.m. Saturday to Monday. R Shuttle service will extend to Whitehall St from 11:45 p.m. Friday to 6:30 a.m. Monday, and again from 11;45 p.m. Monday to 5 a.m. Tuesday.