Vampires are famously vulnerable to sunlight - however it is important to note that while sunlight might cause irritation to exposed skin, it's the EYES that need to absorb the light before fatal immolation will occur.
A vampire with their eyes shut can stumble around for hours without perishing. Most are quite safe on a cloudy day with a wide brimmed hat.
And sunglasses? Be wary of anyone who looks like they're cosplaying The Matrix.