Historically and as of 2026, January and February are the cheapest months to fly to Tokyo. This is the "low season" for Japanese tourism because the weather is quite cold (though often sunny and dry), and the major holiday rushes of New Year's and the spring Cherry Blossom season (Sakura) are either over or haven't begun yet. You can often find round-trip flights for 30% to 40% less than you would pay in April or July. Another "budget window" occurs in late May and early June, after the "Golden Week" national holidays but before the humid summer heat and the start of school vacations. To get the best deal, avoid traveling during late March/early April (Cherry Blossoms), late July/August (Summer festivals and heat), and the last week of December. Booking your mid-winter flight at least 3 to 4 months in advance will usually net you the absolute lowest fare, and you'll benefit from much smaller crowds at popular spots like the Shibuya Crossing or the temples of Asakusa.