HEATING
The heating question is easy.
You will need a heating system in Granada from about 5th November until the end of April.
You could widen that by a week or so to cater for freak weather.
The Spanish expression is:
"hasta el cuarenta de mayo no quites el sayo"
The translation is:
Until the 40th of May don't take your coat off.
The nearest English expression is
Never cast a clout until May is out.
(clout is an old word for cloth)
These expressions mean that until June you will need a coat.
Betwen the end of December and the start of March you will need a fairly good heating system because it gets cold at night.
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COOLING
The air-conditioning question is more difficult.
20 years ago almost nobody had air-conditioning in Granada.
Nobody was very bothered. On some days in the summer it was a bit too hot but so what.
Now with economic progress or as some people would say "the wimping down" of society a lot of people have air-conditioning and Granada will now use several gadzillawatts of electricity during July and August.
In my opinion air-conditioning is only really useful on about 15 days between the first of July and the 20th of August and on about 5 days it is really good to have it.
The trouble is that is not possible to predict exactly which days will be very very hot.
Granada is about 670 metres above sea level so the temperature at night is very rarely very uncomforable. Also Granada has a dry heat which is much more comfortable that a humid heat.
I now have air-conditioning in my own house. At the time of writing it is the 10th of July 2009 at 13:40 the temperature is 27.9C. I don't have the AC on I just have the window open. In the last week I have only used the AC a couple of times.
Is AC necesary for you son?
In my experience of young people if your son has to pay for the electricty out of his own allowance then he won't use AC even if he has it. He will prefer to spend his money on going out.
However if you are paying the electricity bills for him he will have the AC on 24 hours per day at 18C even when there is is nobody there. If it gets too cold then rather than turn it down he will open the windows to warm it up.
