A rare phenomenon was reported this morning, April 3, in which several northern areas inexplicably became dark for around ten minutes.

In Hon Gai, Halong City, people had to turn their lights after the sky turned dark. Confused citizens rushed outside to witness the phenomenon, which occurred without warning. One resident said, "I was in my house and everything suddenly became dark. I ran outside to see what was going on. It looked like a solar eclipse. Yesterday's weather forecast didn't say anything about this."

Nguyen Tien So, head of Quang Ninh Centre for Hydro-Meteorological Forecasting said, "This is a natural phenomenon which can be caused when a mass of cumulus clouds temporarily block out the sun. It usually happens just before or after summer storms. Once the storm passes, everything goes back to normal."

The deputy head of the Centre for Hydro-Meteorological Forecasting for the Northeast region, Nguyen Vu Thang, also said a large cumulus cloud could be the cause for such an event. "Judging by the way the sky turned back to normal so quickly, I would say that this was most likely the cause."

This same phenomenon was reported in Ninh Binh Province from 8:05am to 8:30am.

Baffled residents

Sky returns to normal after 10 minutes

Sky turns dark in Ninh Binh