A beautiful blood-red sunset formed over the sky in Rizal, the Philippines on July 19.

Onlooker Jan Michael Alejo said he was lucky to have captured it on video since it only appeared briefly before nightfall.

He said: "Yesterday's red sunset I think is the most blood red sunset I've seen. It's like I'm in the beach when I'm really just in the city."

The red colour in the sky at sunset is due to an effect called "Rayleigh Scattering." This means a large amount of blue and violet light has been scattered so you see a longer wavelength which appears to be red.

A red sky at night also means that high pressure is moving in from the west and the next day will be sunny.

While a red sky in the morning signals that high pressure has already moved east, giving way to low pressure with wet and windy weather.