Understanding Tokyo Weather: Tokyo’s Tenki

WeXpats

2021/03/15

Life in Japan

Checking the weather is a must for most people before proceeding with their daily activities. People living and traveling in Tokyo are no exception. Here is a short explanation about weather and how to read weather forecasts in the city, and people traveling or moving to Tokyo should become familiar.

Table of Contents

Weather Forecast in Tokyo
Tokyo weather per month
Sites and Apps to be your guide to Tokyo weather
Summary

Weather Forecast in Tokyo

The main agency responsible for weather forecasts is the Japan Meteorological Agency (JMA). They also issue earthquake, volcanic and other weather-related warnings.

How to read or understand a forecast

When you visit Tokyo or any place for that matter, it's often important to understand how to read weather forecasts because it may affect your planned activities.

Of course, apps are available in English, but here are some of the weather terms you should be familiar with in Japanese.

Let’s use a week’s prediction for Tokyo’s weather by the Japan Meteorological Agency (JMA) as a reference. Tokyo’s weather is the very top of the chart, marked by 東京地方 (Tokyo Region) and 東京 (Tokyo). The numbers going across the top next to 日付 (hizuke - date) are of course, the dates of the week.

One week weather prediction for Tokyo (JMA)

The pictures of the weather conditions should be straightforward enough.

Under that is 降水確率 (kousui kakuritsu) or probability of precipitation.

And under that is 信頼度(shinraido) which means how reliable is this percentage. In the weekly chart, they make a prediction starting the day after next. (If you want a prediction for today and the day after, you should check the 3-day weather forecast here. You can even get a precipitation probability based on time.) On the weekly forecast, the 信頼度 is shown from an A - C scale, A being the most reliable and C being the least. C means that the weather and amount of precipitation is likely to change depending on the day prior compared to B.

And last is 最高(°C) －saikou or the high of the day and 最低(°C) - saitei or the low of the day. Again, more accurate would be the daily forecast linked above.

Also a pro-tip is to know the weather in other regions of Japan, you can toggle the dropdown menu from 東京都 (Tokyo) to other prefectures.

Tokyo temperature and precipitation

Tokyo experiences rainy season during June and July, making an umbrella an essential part of your trip. During summer, Tokyo's temperature is very hot, along with high levels of humidity as well, making things seem very wet and muggy. Typhoon season follows summer in September and October, making the umbrellas a necessity again. When winter comes, the weather ranges from cold to moderate, with very few snowy days recently if any in a year. When it comes to precipitation, the city averages 1,500 millimeters annually.

※ United Nations Educational, Scientific and Cultural Organization, "Greater Tokyo Region (Japan)," p.1

Writer's Pick

Tokyo weather per month

When you are planning to visit Tokyo, you may probably wonder when the perfect season or time is to go. Having knowledge of its weather will certainly bring you an idea prior to your visit. Here are the averages from 2020 to be used as reference for your future trip! Of course, things can change in the future as weather conditions fluctuate yearly.

January	January is usually the coldest month and season in Tokyo. The daily average temperature was 7.1°C, with the lowest reaching 0.6°C and the highest reaching 18.6°C in 2020. You may want to experience the cold in Tokyo but make sure to wear and bring soft and thick coats, sweaters, gloves, scarves and any other necessities that will ease the cold as you travel around, as well as an umbrella for occasional rain.
February	The daily average was 8.3°C and the highest recorded temperature being relatively the same at 18.2°C but the lowest reached -2.1°C, making it even colder in some moments than January. Same advice for clothing follows the one for January.
March	It’s still chilly this month but the average daily temperature rose to 10.7°C, with the highest being 16°C and the lowest at 6.2°C. Cherry blossoms start blooming at the end of the month, and the weather is mildly chilly and perfect for viewing the flowers.
April	Many people plan their trips around the end of March to early April as the perfect season to visit Tokyo for the cherry blossoms. The daily average was 12.8°C with the highest being 18.2°C. But April had the most rainfall in 2020 with 296.5 mm so bring an umbrella. Also the rain can cause the cherry blossoms to fall sooner than expected.
May	May is considerably warmer with the daily average reaching 19.5 in 2020, the highest being 24 and the lowest being 15.6. You can walk around in a light jacket that you can take off during the day when it’s warmer.
June	June (and July) is the weird month where it’s warm and getting hot, yet it rains a lot.Rainy season starts and saw 212.5 mm of rain in 2020. The daily average temperature was 23.2°C, with the lowest being 19.8°C and the highest reaching 27.5°C. A light rain jacket would be helpful.
July	July is still the rainy season! In 2020, it saw 270.5 mm of rain in the month. Temperatures were slightly higher all around than June, with the daily average temperature being 24.3°C.
August	August is usually the hottest month of the year. In 2020, the highest temperature recorded was 34.1 with a daily average of 29.1. The humidity ensures that you’ll still be feeling the heat at night, unfortunately. Many people take day trips out of Tokyo to the beaches of Chiba and Kanagawa.
September	Here comes the typhoons. In 2020, September saw 117.5 mm of rain. But the daily average dropped to 24.2 with some still very hot days but cooler overall.
October	October was even more rainy than September in 2020, with 205 mm of rain. However the weather is much more bearable, with the daily average being 17.5, making things comfortable to get ready for autumn.
November	The amount of rain and the temperature steeply drops to welcome autumn. In 2020, the highest daily temperature was 18.6 but the lowest was 10.1 with a daily average of 14.0. Wearing a sturdy jacket or a light coat and carrying around an extra layer just in case as you stroll around and enjoythe autumn leaves is advised.
December	December 2020 was very similar to January 2020, with a daily average temperature of 7.7 . However, it rained considerably less than it did in January. As it gets quite cold, packing a thick jacket or coat is advised.

※Japan Meteorological Agency, “2020 Monthly Figures”

Sites and Apps to be your guide to Tokyo weather

For a deeper understanding of the weather forecasts of Tokyo and to stay updated daily, you can search for the websites of the Japan Meteorological Agency and AccuWeather on the internet. The websites were created for your convenience to visit the city without feeling anxious about weather conditions while traveling. Apps may also give you more specific weather conditions by location if you enable location settings rather than by entire prefecture like JMA.

You can also download the Weather Japan app for more understanding of weather forecasts. It is a multilingual weather app that provides forecasts around Japan especially in Tokyo. You may also search for other locations in the app.

Summary

Prior to visiting Tokyo, it's indeed very important to know the seasons and corresponding weather conditions of the city. Weather in Japan of course varies from location to location. Having background knowledge of its weather and how to read the basic forecast in Japanese as well as having the right resources may be the biggest help to you when you get there. Traveling around Tokyo might be tricky if you don’t plan for the weather ahead of time. Thus, understanding their weather is a must when you are planning to visit the city and have the best time.