If you're going on a trip, you'd want it to be sunny, right? But Okinawa Prefecture actually gets a lot of rain.
Due to its subtropical climate, Okinawa Prefecture enjoys warm weather year-round and is a globally popular tourist destination known for its beautiful beaches and blue seas. While there are many days when the temperature exceeds 25 degrees, it rarely reaches 35 degrees or higher, and Okinawa is often referred to as a summer retreat.
Ranking of Sunny Days on Okinawa Main Island by Weather Occurrence Rate
When planning a trip, it’s most important to know which month has the clearest skies so you can enjoy the beauty of the ocean to the fullest. When we previously conducted a survey on Okibura’s Instagram asking our followers, “Why do you go to Okinawa?” about 90% of the responses were “To see the beautiful ocean.”
To see the beautiful ocean, it has to be sunny. So, when will it be sunny? That’s the key question.
Japan Meteorological Agency “Weather Occurrence Rates”
What we always refer to here is the “weather occurrence rate” published by the Japan Meteorological Agency. For Okinawa Prefecture, data observed from 1991 to 2020 at four locations—Naha, Minamidaito Island, Miyako Island, and Ishigaki Island—has been made public. The data classifies weather conditions for each day—rain, cloudy, or sunny—and quantifies them numerically.
Weather Determination Criteria and Priority Order
| Weather | Evaluation Criteria | Priorities |
| 雨 | When daily precipitation of 1.0 millimeters or more is recorded | １ |
| Cloudy | When daily precipitation is less than 1.0 millimeters and the average daily cloud cover is 8.5 or higher | ２ |
| Sunny | When daily precipitation is less than 1.0 millimeters and the average daily cloud cover is less than 8.5 | ３ |
Quote:Okinawa Meteorological Observatory: “Weather Occurrence Rates by Region (%)”
How much is 1.0 millimeters of daily precipitation?
It’s drizzling. If you walk outside for a bit without an umbrella, you’ll only get slightly wet. It doesn’t last long; it feels like the very beginning of a rain shower or a brief light drizzle. The ground is slightly wet, and you can see water droplets on leaves and car hoods. Generally speaking, this is the kind of rain that makes you think, “I might want to bring an umbrella just in case.”
What does a daily average cloud cover of 8.5 or higher mean?
When I look up at the sky, it’s almost entirely covered by clouds, and there’s hardly any blue sky in sight. It feels like a light rain could start any moment. With the sun hidden from view, it’s a day with a somewhat dark and heavy atmosphere.
Now, based on the “weather occurrence rates at the Naha station,” we’ll present a ranking of the monthly sunny-day rates for Okinawa Main Island from January through December. Please use this as a reference when planning your trip.
Percentage of Sunny Days from January to December (Main Island of Okinawa)
Did you think, “Huh? There aren’t many sunny days!”? That’s just how it is, lol.
Monthly Rankings by Highest Percentage of Sunny Days
Main Island of Okinawa (Naha): Annual Probabilities of Sunny, Cloudy, and Rainy Days
Based on a calculation of all observational data from the Naha station (1991–2020), the annual weather occurrence rates are as follows: sunny days 49.71 TP3T, cloudy days 19.21 TP3T, and rainy days 31.11 TP3T.
That’s exactly why I want to visit Okinawa Main Island from July through November, when the annual probability of sunny days exceeds 49.7%!
Okinawa Main Island (Naha): The Gap Between First and Last Place
On the main island of Okinawa (Naha area), October—which ranks first—has a sunny day rate of 60.71 TP3T. June, which ranked last, had a sunny day rate of 37.71 TP3T. The difference is approximately 1.6 times. Even for the same trip to Okinawa, simply being mindful of the time of year can change your chances of experiencing sunny days. (June is the rainy season, so the sunny day rate is low.)
Main Island of Okinawa (Naha) by Swimming Season
The swimming season in Okinawa generally runs from April to October. (Depending on the location, some beaches are open as early as March or as late as November.)
You'd want to go swimming on a sunny day at the beach, right? In that case, I think the best months are July through October, when the number of sunny days exceeds 50% and ranks among the top four!
Summary
So, if you’re hoping for a sunny trip to the main island of Okinawa, October offers the best chances! If you can’t make it in October specifically, traveling to the main island between July and December (the second half of the year) will increase your chances of having sunny weather!
As long as the weather is nice, the ocean will be blue, you’ll feel great, and I think you’ll be satisfied. Please use these tips as a reference when planning your trip to Okinawa!
