Don't mistake cooler outside temps for blown headgasket. Of course not seeing how much smoke is coming out and when it does it makes a difference. If it does it no matter how long you drive the car, not just during warn up, then yes you may have a blown gasket.
Are you loosing any coolant?
Is your over flow bottle emptying or over filling?
Are your hoses REALLY hard? Over pressurized?
Take off your oil cap. Is it coated with tan cream (oil and coolant mileshake)?
Pull out your dipstick, are there any water droplets on it or is the oil higher than normal?