Ogasawara Islands to Achieve Japan's Highest Weather Observation Density Through Digital Innovation

The Ogasawara Islands, a UNESCO World Heritage site comprising over 30 islands, are home to approximately 2,500 residents. Despite being roughly 24 hours by ferry from Tokyo, the islands attract around 30,000 visitors annually, drawn by their extraordinary natural beauty and unique ecosystems.

Yet the islands have long grappled with a significant challenge: unreliable weather forecasting.

Unpredictable localized thunderstorms and sudden downpours not only disrupt residents’ daily lives but also create safety concerns for visitors. To tackle this longstanding issue, Weathernews Inc. has joined forces with the Tokyo Metropolitan Government to launch an innovative new initiative.

Ogasawara Village, Tokyo Metropolitan Ogasawara
Subprefecture, and Weathernews Sign Agreement to Deploy AI Weather Forecasting Technology

The root cause of inaccurate forecasts in Ogasawara is insufficient observation infrastructure. Situated approximately 1,000 km south of Tokyo in the Pacific Ocean, the islands fall outside the range of the Japan Meteorological Agency’s weather radar network. Furthermore, only one AMeDAS observation station exists across the entire island chain, located on Chichijima.

The infrastructure gap is clearly reflected in the “precipitation capture rate,” a metric that measures how accurately rainfall is predicted in advance. While Japan’s national average is 80%, Ogasawara’s rate is only 59%.

In practical terms, this means rain can occur even when forecasts call for sunny or cloudy skies.

A localized thunderstorm in October 2023 caused significant flooding damage in the area. Many residents have learned to rely on personal experience and intuition, often thinking, “The forecast says cloudy, but it feels like it might rain today.”

To improve forecast accuracy and address the increasing threat of severe weather events, Weathernews has entered into a formal agreement with Ogasawara Village and the Tokyo Metropolitan Government’s Ogasawara Subprefecture.

Together, they have launched an initiative to create ** “Japan's Most Advanced Weather Monitoring System with Unprecedented Observation Density.”**

A survey conducted among residents at the project's outset revealed the extent of current challenges. When asked about their overall satisfaction with existing weather information sources (including AMeDAS and radar data):

• 34% responded “neutral” • 33% responded “dissatisfied”

The main reasons for dissatisfaction included:

• “Unexpected rain” • “Wind and wave conditions differed from forecasts, affecting work and leisure”

These concerns accounted for nearly 70% of responses, underscoring the real-world impact of forecast inaccuracy.

However, when asked whether they would use more detailed, Ogasawara-specific weather information if available, over 90% responded that they would, demonstrating strong community support for the initiative.

Source: “Toward Making Ogasawara the Most Advanced Weather DX Area with the Highest Observation Density: Survey Results on the Use of Weather Information (FY2025),” Tokyo Metropolitan Government Ogasawara Subprefecture (based on materials from the Ministry of Internal Affairs and Communications)

Deploying IoT Sensors and AI Technology to Enhance Forecast Accuracy Cost-Effectively

As part of this initiative, Weathernews will deploy its live cameras and the "Soratena Pro"—a high-performance weather IoT sensor that is the first in Japan to receive official recognition as supplementary observation equipment for forecasting operations.

These sensors will be installed across Chichijima and Hahajima to create a high-density, proprietary observation network capable of monitoring hyper-local weather conditions.

Traditional weather forecasting has relied on large-scale radar systems costing hundreds of millions of yen per unit. This project takes a different approach: by combining compact sensors with AI technology, it achieves high-precision forecasting at a fraction of the cost.

The collected observation data and forecasts will be shared with local government officials and residents through push notifications, and will also be accessible via the free Weathernews app and website.

This initiative aims to provide enhanced safety and peace of mind not only for residents but for all visitors to the islands.

Expanding the Network: Deploying Soratena Pro Sensors and Live Cameras Across the Islands

To support the project, a field survey for sensor installation was conducted in December 2025. Over the course of about a week, teams evaluated installation sites, verified data collection feasibility, and prepared permit applications.

Carrying approximately 20 kg of equipment, including batteries and sensors, the team walked 10 km to test data acquisition.

Communication tests were successfully completed.

By February 2026, installation locations had expanded to: • 6 Soratena Pro sites • 7 live camera locations across the Ogasawara Islands

Weathernews staff who visited Ogasawara for the surveys and installations all returned captivated by the islands' natural beauty—and its local flavors.

The team was particularly impressed by the island's renowned tomatoes. Even a single tomato, gifted as a souvenir, surprised everyone with its exceptional texture, sweetness, and umami. The enthusiasm was contagious! 🍅✨

Since most of these tomatoes are consumed locally, opportunities to taste them outside the islands are exceptionally rare—making the experience all the more memorable.

Staff also returned inspired by Ogasawara's unique wildlife, including its endemic bat species, and the crystal-clear waters surrounding the islands. The team's passion for the project was clearly deepened by experiencing firsthand the extraordinary natural environment they're working to protect.

Developing an AI Forecasting Model Using a Proprietary Observation Network

Data from the installed live cameras is already accessible through the Weathernews app, providing real-time views of current conditions across the islands.

Looking ahead, Weathernews will develop a proprietary AI forecasting model by integrating local observation data with satellite imagery. Leveraging forecasting technology that has achieved No. 1 accuracy rankings for three consecutive years, the company aims to deliver highly precise forecasts that enhance safety and quality of life for both residents and visitors.

Beyond Ogasawara, Weathernews plans to apply the insights and methodologies gained from this project to other remote and underserved regions. By expanding this technology, the company seeks to support broader community resilience and contribute to a more sustainable society.