Flights from Deer Lake to Buffalo lean towards being more expensive in December. Prices are generally better when you fly from Deer Lake to Buffalo in August, with the cheapest ticket starting at C$ 313.
When travelling, it's generally smart to pack in preparation for rain or any other conditions that may arise. The rainfall in Deer Lake is roughly similar to Buffalo. You can assume this to be the case over the next 19 days.
Temperatures around the 27 °C's can be experienced in July. The weather in Buffalo is hotter than in Deer Lake. Plan for potential changes in flight availability as peak weather approaches in this location.