Don't Forget: Blue Moon On The Rise Friday In Montgomery County

Once in a blue moon? That’ll be Friday, the first in nearly three years.

A blue moon occurs when there are two full moons in the same month. Because a moon cycle lasts for about a month, the timing has to be just right to get two in the same month.

July 2 was a full moon. July 31 will be, too. Hence, blue moon 2015.

The last time this happened was August 2012, when there was a full moon on August 31 that year.

Weather will be milder on Friday in Montgomery County for the big night than it has been for much of the week, as scorching temperatures and lagoon-like humidity made some afternoons and evenings unbearable.

The moon should be visible as the evening progresses, but the full brilliance of the full moon should be in view by nightfall at 9 .m.

Here’s the hour by hour forecast, courtesy of Weather.com:

5 p.m. 88

6 p.m. 87

7 p.m. 85

8 p.m. 81

9 p.m. 78

10 p.m. 76

11 p.m. 75

The next blue moon will be an even rarer event.

Because of their timing coinciding with a leap year, both January and March of 2018 will have a blue moon. The last time that happened was 1999.

To answer a common question: no, the moon won’t actually be the color blue.

While there are some conditions that can cause the moon to appear a shade of blue—smoke, a concentration of certain particles—the name has nothing to do with the moon’s color.

It dates back to a 16th-century piece of literature using the word “belewe,” to betray, to refer to a moon that doesn’t properly mark the end of a farming season.

The “blue” caught on in the early 1900s and now generally refers to two full moons in the same month.