As the Geneva Vikings football team faces off Friday night against Wheaton North, there will be an omen in the sky: a blue moon.

Just as the moon isn’t made of cheese, it isn’t really blue either, but on Friday the phrase, "once in a blue moon" will apply. August will end with the second full moon of the month.

The month of August started with a full moon, with the first one taking place on Aug. 1, and ends with the full moon Friday.

Modern folklore has dubbed the occurrence of two full moons in a month as a blue moon, according to the science website EarthSky.org. The blue moon happens only every two to three years. The next blue moon isn’t expected until July 2015.

The National Weather Service says Friday it will be hot, with temperatures topping out at 95 degrees in Wheaton. A slight chance of storms is possible, but those are likely after 1 a.m., so the sky should be clear for blue moon viewing. 

And hopefully, that blue moon Friday will be a good omen for the blue and white.