You might spend a lot of your holiday inside, but if you're planning to venture beyond the casino, taking a look at local weather data can help you. The hottest months are usually June and July, with an average temperature of 29°C, while the coldest months are January and February, with an average of 21°C. The rainiest months in Dong Hoi are October, September, November and December, with each month seeing an average of 474 mm of rainfall.