Not normal IMO. This post from robbo mcs was posted on NAM and explains all:
To understand what is going on here, you have to understand that there is a temperature sensor that tells the ecu what the temperature is, and a mechanical thermostat that opens at a certain temperature and regulates water flow and therefore the temperature.
What is supposed to happen is that the mechanical thermostat is set to 105C (221). When the car is moving with good radiator flow the temp should stay at roughly 105. Once the temperature goes > 106 (223) the electric fan cuts in. This usually because the car is stationary, with no airflow.
The problem is that the mechanical thermostats seems to be a little inaccurate and out of sync. There are a whole lot of thermostats that seem to run at 107-108C (224-227F). What happens in this instance is the thermostat doesn't open water flow properly until it reaches its temp, so driving around the temp will be 107-108C. This confuses the ecu, as the temperature sensor reads >106, so it activates the fan.
It is also possible to have the reverse problem, ie an accurate thermostat but a miscallibrated temperature sensor which reads the water temp higher than it actually is, which can produce exactly the same problem.
If this is happening, the fan is not just running when you stop the car, but nearly all the time, even driving around. When you stop it will run until the temp drops to the 106C number.
So if you are lucky and have a "normal" thermostat that runs around 104-105C you won't get the fan operating when you stop very often. If you have one of the thermostats that runs at 106-108C you will get it a lot.
Does this matter? Not really from an engine point of view. However, it must be increasing the risk of fan failure in the long run.
Also, just out of interest, there are actually 2 thermostats operating in 2 stages. The main one runs as described above. There is a second one set to 85C (185F). When the ecu detects high turbo load from aggressive driving etc it opens the second stage, and the temps drop down significantly.
ps: I've got a feeling the non-turbo Cooper has a single-stage fan but the principle's the same. And miniuy's dealer fix was probably to resite a new thermostat in a coolant hose nearer the rad. I've had this done under warranty too...