Allegiant Air typically maintains a low cancellation rate, around While generally reliable, remember that unforeseen circumstances can still lead to cancellations. For added flexibility, consider Trip Flex. Concerned about flight cancellations?The cheapest days to fly on Allegiant Airlines are generally Tuesdays, Wednesdays, and Saturdays or. These days typically have lower demand, which results in reduced Airfare prices compared to peak travel days like Fridays and Sundays