There's nothing like an all-inclusive holiday in Watford City to rejuvenate you, especially when you know what to expect from the elements. Here's some information to help you choose when to book: The hottest months are usually July and August, with an average temperature of 20°C, while the coldest months are January and February, with an average of -7°C. January and February are the driest months, while May and June are the rainiest months.