Depends on your airline. From memory last year it dropped to 23KG for Air Canada and others seemed to be roughly similar for all trans-atlantic destinations, but with all the current problems I'd check with whoever you're flying with as they all seem to have their own baggage rules currently.
Most airlines have a size restriction rather than a weight restriction to the USA - 2 pieces with maximum dimensions which you'd have to look up. There is also an overriding maximum of 32kg per case.
Charter flights to Florida may well have a much smaller allowance - the above applies to scheduled flights.