With temperatures reaching as high as 101 today, it was perhaps inevitable there would be problems on the Penn and Camden MARC lines. The only surprises are that they are relatively few and didn't crop up until after 5 p.m. Here's the latest from the MTA:

Last updated: July 07, 5:12 PM
 

Penn Line Commuters:  UPDATE MARC Train 534 departing Washington Union Station at 5:15 PM will make all stops to Baltimore to accommodate passengers from Train 432.  Expect overcrowding condition.

MARC Train 432 at  Washington Union Station (Depart 4:40 PM) is delayed due to overhead wire problem. Expect 15-20 minutes delay. Update to follow