Weather Forecasting Media: [tenki.jp]
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Professional weather forecasting by Japan Weather Association is published and available through our website and smartphone application free of charge.

The tenki.jp website and application are operated by Japan Weather Association and ALiNK Internet Co., Ltd.
URL: https://tenki.jp/

The annual page views total 5.9 billion PV (sum of Web + previous standard App values from April 2023 to March 2024, rounded down).
In addition to weather forecasts essential for daily life, users can check specialized meteorological information and disaster prevention and mitigation information for earthquakes, tsunamis, and more.
Another popular feature is the “Key Points Commentary by Weather Forecaster”, where JWA meteorologists provide updates on weather and disaster prevention and mitigation every day.
All information published on the website is free of charge, and regularly updated to keep up with all necessary news and developments.
The weather information on tenki.jp is a product that is analyzed by a variety of observed data, forecast information, and the JWA’s own forecast model. However, please understand in advance that the forecasting models have limitations in terms of time and space, and there may be discrepancies between actual weather conditions and forecasts due to the effects of local topography and unpredictable sudden weather changes.

tenki.jp, Update frequency

The weather content is updated regularly with the latest information available, and additional information updated as needed.
The update intervals, announcement times and observation times of the main information are as follows:
* Updates are made slightly later than the announcement and observation times.
*For more detailed information regarding each tenki.jp service, please go HERE.

■ Weather forecast

#All times written in JST
〇 Weather forecast for:
Today’s・Tomorrow’s・3-hour・1-hour・2-weeks
Municipal weather forecasts are updated and published hourly, 24 times a day.
〇 World weather
The forecast is updated 2 times a day, at 05:00 and 17:00.
The current weather forecasts for major cities are updated 8 times a day, observations made at 00, 03, 06, 09, 12, 15, 18, and 21:00.
* *Some locations do not have observations at certain times, and the number of observations varies for each location.

〇Long-term forecasts
1-month forecasts are issued once a week, and 3-months forecasts are issued once a month.
Forecasts for the warm season are issued in February, and the cold season forecasts are issued in September.
〇Raincloud radar (actual conditions):
Observed and updated every 5 minutes
〇Raincloud radar (forecast):
Updated every 30 minutes
〇Raincloud radar for your current location
Updated every 5 minutes
〇PM2.5 distribution forecast:
Updated once a day at around 8:00.
Precipitation, wind speed and wind direction on the time series page are updated at the same frequency as the 1-hour and 3-hour forecasts.
〇Weather impact on road conditions forecast (road weather):
Updated 8 times a day, approximately every 3 hours.
Announced at 01, 04, 07, 10, 13, 16, 19, and 22:00.
〇Yellow sand dust information:
Updated once a day around 4:00.
Precipitation, wind speed and wind direction on the time series page are updated at the same frequency as the 1-hour and 3-hours forecasts.

■ Observation

〇Raincloud radar (past):
Updated every 30 minutes
〇AMeDAS:
Temperature, precipitation, wind direction, wind speed, and sunlight hours are observed and updated every 10 minutes. Snow depth is observed and updated every hour.
〇Past weather:
Data for the previous day is updated around 01:00.
The weather overview for the previous month is updated by the middle of the following month.

■ Disaster prevention/mitigation information

〇Warnings and Advisories
Updated as needed in accordance with the special warnings, warnings, and advisories issued by the Japan Meteorological Agency .
*The criteria for announcement vary depending on the region, but when special warnings, warnings, and advisories are issued, please be vigilant and pay close attention to weather information.
〇Earthquake Information
Updated as needed as earthquake information is announced by the Japan Meteorological Agency.
〇Tsunami Information
Updated as needed as tsunami information is announced by the Japan Meteorological Agency.
〇Volcano Information
Updated as needed as volcano information is announced by the Japan Meteorological Agency.
〇Typhoon Information
Updated as soon as typhoon information is announced by the Japan Meteorological Agency. While a typhoon is forming, weather forecasts will be announced every three hours, and if the typhoon approaches Japan and there is a risk of disasters occurring, information will be announced every hour.
*If a typhoon changes to a tropical storm or temperate depression information will no longer be announced, but please continue to pay close attention to the latest weather information.

■Weather maps

〇Weather map
The weather map is updated seven times a day.
Update time at: 03, 06, 09, 12, 15, 18 and 21:00 observations, an update approximately every third hour.
Weather maps are updated as follows:
– Next day forecast, updated three times a day around 5:30, 10:30 and 15:30.
– Forecasts for 2 days later, updated three times a day around 11:00, 17:00 and 20:00.
– Forecast for 3 days later, updated twice a day around 11:00 and 17:00.
〇Meteorological satellites
Weather satellites in the area of Japan are monitored and updated every 30 minutes.
〇Global satellites
Observations are made and updated four times a day at 3.00, 9.00, 15.00 and 21.00.

■ Index information

12 times a day at even-numbered times.

■ Leisure weather

〇Weather for travel and outing spots
Announced 24 times a day, same frequency as “Today and Tomorrow’s Weather.
〇Weather forecasts for campsites
Announced 24 times a day, same frequency as “Today and Tomorrow’s Weather.

Inquiries regarding tenki.jp

For enquiries regarding tenki.jp, HERE.
Advertisement opportunities on the tenki.jp website, HERE.
Inquiries to cover or publish regarding tenki.jp, HERE.

*Unauthorised publications and use of data without permission is not permitted. Permission must be obtained in advance from the Japan Weather Association.
(For details, please refer to the ‘tenki.jp Terms of Use’ here.)
The name ‘tenki.jp’ is a registered trademark of the Japan Weather Association (Registration No. 6129427).
The ‘tenki.jp’ logo mark is a registered trademark (No. 5763293) of the Japan Weather Association and ALiNK Internet Co.