Even during the winter months apply SPF !
Aside from helping to protect you from skin cancer it is The best ant wrinkle cream ever.
Wear it every day, no matter the weather.
Apply 30 mins before sun exposure. Re apply 90 mins if exposed to continual high temperatures.
Adjust your SPF level in line with the sun exposure.
If you apply SPF 30 and then have a SPF 15 in your make up, your level of protection is SPF30. The numbers are not added together to increase protection.