Hailey Cox, 10, plays a game with her grandmother, Linda Betts, not pictured, as they settle in for the evening on Colorado Boulevard. (Marcus Yam / Los Angeles Times)

A drizzle could make the ground wet in the hours leading to the Rose Parade in Pasadena Monday, but forecasters are not expecting any real rain.

“It’s a pretty good chance the ground will be wet — damp is what we’re expecting. Not like measurable rain,” said National Weather Service meteorologist Carol Smith. More likely is “light showers or drizzle that can get the ground wet.”

The drizzle is more likely in the early morning hours, and it’s possible that the drizzle could extend into the early part of the parade, said weather service meteorologist Curt Kaplan. It’s also possible the drizzle could stop, and the parade itself will start with mostly cloudy conditions that lead into partly cloudy skies by the time it ends.

If Monday’s Rose Parade is spared a downpour, officials will undoubtedly point to the celebration’s “Never on Sunday” rule as a reason, in which the parade is moved to Jan. 2 if New Year’s Day falls on a Sunday. (But for those who were wondering: skies were clear on the morning of Jan. 1 in Pasadena.)

The custom of shifting the parade a day later when New Year’s Day falls on a Sunday began in 1893 to avoid riling the horses hitched outside church and possibly disrupting the services inside.

The flower-bedecked procession has been rained on only 10 times in its 127 years. And this is only the 15th time in its 128-year history that the Rose Parade will be held on a Monday, Jan. 2.

The last time the rain came was in 2006 — a year that the parade was also held on a Monday, Jan. 2. And it came in a downpour.

As The Times reported back then:

Cheerleaders kept their game face through cascades of running mascara. Flag twirlers had to deal with sodden pennants that bunched up like wet laundry. And hundreds upon hundreds of marching band members were soaked down to their arpeggios.

Times staff writer Gale Holland contributed to this report.

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