I'm new to Saabdom too,had my 900 about 3 months.All the Saab specialist I've asked said the needle in the middle and frequent cooling fan are normal,indeed optimal.I'm in Florida,and the average temp is
100(farenheit).Years ago I had a Volks that did the same in hot weather.LIke the othe guy said,just check the coolant frquently.
A whlie ago I made a very long trip in her, in average 90 degree weather with the AC on constantly,with no sign of overheating.
Ciao