A quake with a magnitude of 3.1 and with its epicentre in the district hit at 8.01am.
Somboon said the quake was caused by a slide of the Nan-Uttaradit fault, which stretches from Nan to Uttaradit provinces.
The quake was the largest magnitude this year in the area, compared to 2.8 tremor that struck on January 31 in Chiang Rai’s Thueng district and a second on April 5 in Chiang Rai’s Muang district.
Thanarat Phummakasikorn, director of Sirikit Dam said the quake’s epicentre was 13 kilometres underground and about 62.5 kilometres from the dam.
Thanarat confirmed that the earthquake had no impact on the dam, which is still open to tourists visiting Uttaradit.