Looking at it more closely it looks like these are the current dates available to book for summer 2017
Sanford (Orlando)
5 Apr – 19 Apr weekly
19 July – 16 August*
*Operates fortnightly
Cancun
3 May – 31 May
19 July – 27 September
Montego Bay (Jamaica)
4 May – 1 June
20 July – 28 September
There is a break in June/July where the aircraft is utilised elsewhere but returns in time for the peak English school holidays.
As mentioned above a reduction in Orlando, probably due to the large programme now offered by Thomas Cook at Stansted and lack of demand outside of peak dates.
Overall an increase on this year's operation with the introduction of the Montego Bay service next summer.
September is not the usual cut off date for the summer season, but this is as far as the programme is on sale. It is likely some routes may continue through October or winter 17/18.
Good things are happening with long-haul leisure routes at Stansted
