A light rain began to fall.

小雨开始飘落。

《牛津词典》

When it does rain, it tends to be a very light rain that isn't troublesome.

下雨了一般也是小雨，不会造成太大的麻烦。

youdao

A light rain drips from the clouds but soon stops.

天空的云彩落下了细雨，但不久就停了。

youdao

A light rain was falling. There was no one else on the road.

VOA: special.2009.06.18

The march began under gray skies and light rain symbolically at the Holocaust Museum, where the murder of six million Jews in World War II is documented and remembered.

VOA: standard.2010.05.23

The search proceeded cautiously for the fourth child as light rain fell throughout the afternoon.

NPR: 1 Child Dead, 1 Missing In Minn. Park Landslide

Farther south, dozens of flights were also canceled at Philadelphia Airport as a light rain fell.

WSJ: A state-by-state look at the Northeast blizzard

Mr. Altschule was also able to explain that light rain was significant enough to melt any snow.

FORBES: The World of Forensic Meteorology