Farmer Ek Chea, 59, was attempting to take shelter at a relative's house when heavy rain and high winds rolled in, district police chief Brigadier General Ung Sam Ol said.
"Unfortunately a lightning strike hit him, causing him to immediately die at the scene," Gen. Sam Ol said, adding that the strike took place during a two-hour storm at about 5pm on Saturday.
"Three cows also were killed instantly by another lightning strike on the same day," Gen. Sam Ol said.
Keo Vy, a spokesman for the National Committee of Disaster Management (NCDM), said the latest nationwide statistics show there has been more deadly lightning strikes this year than in the same period last year.
A total of 39 people have died from lightning strikes in the first five months of 2016, up from the 28 deaths last year, while the number of injuries caused by lightning strikes is up from 15 in the first five months of 2015 to 46 this year.
Animal deaths caused by lightning are up as well, from 25 to 27.
A total of 184 people were struck by lightning last year in Cambodia, 107 of whom were killed - a dramatic jump from the 75 fatalities in 2014, according to the NCDM. The odds of being killed by lightning in Cambodia in 2015 were 7.1 in a million, some of the highest in the world.
Comment: See also: Three killed by lightning strikes in Thailand and Cambodia; 30 dead for the latter in first 5 months of 2016
Cambodia has recorded 18 deaths from lightning so far in 2016