October to February: the short winter and the jobs that belong in it
Winter is when the pool finally stops fighting you, and the temptation is to stop paying attention. Resist it, because the cool months are the only sensible time for disruptive work. Anything that requires draining or half-draining the pool — acid washing tired plaster, regrouting the tile line, replacing underwater lights, repairing expansion joints — belongs between November and February, when refill water will not immediately cook and the pool being out of action for a few days costs nothing socially.
January is heater season. Unheated pool water in Dubai bottoms out around 18 to 20 degrees, and colder still in inland Al Ain, which is genuinely uncomfortable for most swimmers. Air-source heat pumps are the standard solution and they are efficient in the mild UAE winter, but they need a pre-season service: refrigerant pressure check, coil clean (a summer of dust will have coated it), and confirmation that the flow switch and bypass are set correctly. Book that in November, not the week of the first cold snap, when every heater technician in the country is suddenly busy.