Okinawa month by month — at a glance
Hover each month for the summary. Click to pin it.
Almost nobody travels to Okinawa for the city. You travel for the water, and the water keeps a timetable. What sets the archipelago apart is that its bathing season is extraordinarily long by Japanese standards — seven months — and that even so, picking the wrong week can leave you under three days of continuous rain or with your inter-island flight cancelled.
01 Seven months of water, from late March to 31 October
In the rest of Japan the beach season lasts six or seven weeks: facilities open in early July and close at the end of August. In Okinawa the beaches hold their official opening — the umi-biraki — in late March or the first days of April, and most keep lifeguards and nets in place until 31 October.
The nets are not decorative. They mark the patrolled area and hold back the habu jellyfish, which turns up in the warm months and is the reason to swim inside the perimeter rather than in whatever empty cove looks good from the road.
Key moments at a glance
Beaches already open, 161 mm and the tsuyu still to come. The most comfortable window of the year.
227 hours of sun, the annual record. Book the first half, before the typhoon peak and the Japanese holidays.
2.2 approaches on average, top prices and the year's heaviest domestic travel.
A 28.1-degree average high, less rain than September and typhoon risk already retreating.
02 The first door closes on 10 May
The tsuyu, East Asia's rainy season, reaches Okinawa before anywhere else in Japan. The average onset is 10 May and the average end 21 June. On Miyako and Ishigaki it tends to arrive about a week earlier. These are six weeks of closed sky, not of afternoon showers.
The numbers back it up. May collects 245 millimetres and June 284, the annual maximum; June's mean relative humidity is 83%, the highest of the twelve months. Swimming is still possible and the water is warm, but snorkelling loses most of its point when the light does not get in and visibility drops.
03 The second door arrives from the southeast
Okinawa is the region of Japan that the most typhoons approach: around 7.7 a year on average, well ahead of the rest of the country. The distribution is not even. August logs 2.2 approaches on average and September 1.9: between them they hold more than half the annual total.
What a typhoon does to a trip is less about wind than about paralysis. Inter-island flights and ferries are cancelled twenty-four or forty-eight hours ahead, shops close and dive trips vanish from the calendar. A single system can freeze three days out of a seven-day week.
A typhoon rarely ruins a trip through what it breaks. It ruins it through what it stops.
04 What is left: two narrow windows
Cross the six weeks of tsuyu and the two peak typhoon months off the calendar, and a seven-month bathing season shrinks to two clear stretches. The first runs from late March to early May: beaches already open, 161 millimetres of rain in April and the archipelago not yet full.
The second stretch is better and less known: from the end of the tsuyu on 21 June to mid-July. July collects 227 hours of sun, the annual maximum, and rains less than June. Typhoon risk exists but has not peaked, and the Japanese school holidays have not fully begun.
And there is a third moment that fits neither window but in practice works best of all: October. The official bathing season runs to the 31st, average highs hold at 28.1 degrees, rain drops to 179 millimetres and typhoons are already retreating. Add that prices fall as soon as August ends.
05 What winter offers instead of swimming
From December to March, Okinawa stops being a beach destination and becomes something else. The mean sits between 17 and 19 degrees, a northerly wind blows and the sky hangs low: January and February gather only 93 hours of sun each, half of July's. Nobody swims without a wetsuit.
In exchange, three things happen that summer does not offer. Humpback whales reach the Kerama Islands to calve between late December and early April, and February has the highest sighting rate. The kanhizakura cherries bloom in mid-January, earlier than anywhere else in Japan, and the Motobu and Nago festivals fall at the end of that month. And the sugarcane harvest begins.
06 How to choose the date
If the trip is about snorkelling, diving and clear water, the choice narrows to three blocks: April, the second half of June together with the first of July, and October. Of the three, October is the safest and cheapest; April the mildest; July the brightest and the one that takes on the most risk.
If the trip is about remote islands, add one rule. The further you want to get — Ishigaki, Iriomote, Yonaguni — the more you depend on short flights and ferries, and the more a typhoon costs you. In August and September, leave two days of slack before the flight home, or simply pick another month.
And if you have time to spare and budget to save, winter has an honest case: you will not swim, but you will see whales, cherry blossom in January and an archipelago that in those months belongs again to the people who live there.
Alexey Komarov The best weather and the worst access fall in the same month.
Nemo bis In California it does not rain in summer, and the coolest place in July is the coast.
Ayanadak123