In general, when booking your flight to Havana, September is the cheapest month on average.
From most locations, booking your flights to Havana around 60 days prior to your departure date finds the best deals.
On average, the cheapest flights to Havana are found when departing on a Tuesday. Try to avoid departing on a Friday, as this is usually the most expensive day.
Generally, when visiting Havana, morning flights represent the best value. noon flights are likely to have higher prices.