Why rain tyres on a dry track?

[mini696]

Why do some teams (testing at Silverstone etc), use rain tryes on a dry track?

Is it just because of cold weather, and they need to do this for temperature reasons?

Is it because its a shakedown and they are using up old tyres?

[manchild]

I think they are testing them to see how long can such tyres be used on dried track. That's important characteristic of the tyre as well as it's performace.

[Venom]

The track was wet in the morning.

[pyry]

also on a particulary cold morning the dry tyres wont reach their optimum operating temperature.