It depends on what part of the cruise you're referring to. Near Southampton it will of course be near the local temperature for that time of year - maybe 20-25C. By the time you're in the North Atlantic, it'll be a lot cooler, maybe 10C or less. You'll definitely need a jacket at night. And when you get to New York, if it's like most Julys it'll be hot and humid - 25-32C and 70% humidity.
titanic
Average temperature/weather during Transatlantic crossing mid September?
I myself have made the transatlantic crossing several times.
Crossing Brooklyn Ferry was created in 1855.
I wanted to visit Europe, so I took a transatlantic flight to London. The first transatlantic flight took place in the early 20th century. The Titanic was unable to complete her first transatlantic crossing. My international communications still rely on the transatlantic cable.
SS United States
Southampton (England) Cherbourg (France) Queenstown (ROI)
crossing the Atlantic
The East River .
This is a matter of opinion and subjective. They both offer quite a good transatlantic product.
Crossing Southampton Road in London while taking a walk on September 12, 1933.
monarch butterflies travel from as far north as Maine and Canada and fly down to south America and Mexico.