The Tokyo area had around 2.1 thousand hours of sunshine in 2024. The highest annual sunshine duration was recorded in 2023, with almost 2.26 thousand hours.

In 2024, the highest monthly sunshine duration in Tokyo was recorded in December, reaching over 233 hours of sunshine. October represented the month with the lowest sunshine duration, with only 111.7 hours.

Context This dataset provides weather data for Tokyo, covering the period from June 26, 2018, to June 26, 2024. The data is sourced from the Japan Meteorological Agency (JMA). According to their usage terms, numerical figures are not subject to copyright and can be freely used.

Content The dataset includes daily weather data for Tokyo with the following columns:

• Date: The date of the recorded data.
• Average Temperature (°C): The average temperature for the day.
• Highest Temperature (°C): The highest temperature recorded for the day.
• Highest Temperature (°C) Datetime: The date and time when the highest temperature was recorded.
• Lowest Temperature (°C): The lowest temperature recorded for the day.
• Lowest Temperature (°C) Datetime: The date and time when the lowest temperature was recorded.
• Total Precipitation (mm): The total precipitation for the day.
• Sunshine Duration (hours): The total duration of sunshine for the day.
• Maximum Snow Depth (cm): The maximum snow depth recorded for the day.
• Maximum Snow Depth (cm) Datetime: The date and time when the maximum snow depth was recorded.
• Total Snowfall (cm): The total snowfall for the day.
• Average Wind Speed (m/s): The average wind speed for the day.
• Maximum Wind Speed (m/s): The maximum wind speed recorded for the day. Maximum wind speed refers to the highest 10-minute average wind speed observed within a specific time period.
• Maximum Wind Speed (m/s) Datetime: The date and time when the maximum wind speed was recorded.
• Maximum Wind Speed (m/s) Direction: The direction of the maximum wind speed recorded.
• Maximum Gust Speed (m/s): The maximum gust speed recorded for the day. Maximum gust speed refers to the highest instantaneous wind speed observed, typically measured over a 3-second period.
• Maximum Gust Speed (m/s) Datetime: The date and time when the maximum gust speed was recorded.
• Maximum Gust Speed (m/s) Direction: The direction of the maximum gust speed recorded.
• Most Frequent Wind Direction (16-point compass): The most frequent wind direction recorded using a 16-point compass.
• Average Vapor Pressure (hPa): The average vapor pressure for the day.
• Average Humidity (%): The average humidity for the day.
• Minimum Relative Humidity (%): The minimum relative humidity for the day.
• Minimum Relative Humidity (%) Datetime: The date and time when the minimum relative humidity was recorded.

Inspiration 1. Climate Change Analysis Analyze Tokyo's weather data to identify climate change impacts and trends over the past four years, aiding in the development of accurate climate models and policies. Note that certain usage restrictions apply under specific laws such as the Meteorological Service Act; see ML-17 and ML-23 for details.

1. Renewable Energy Optimization Optimize solar and wind energy deployment in Tokyo by assessing sunshine and wind data, improving renewable energy efficiency and supporting sustainability goals.

2. Urban Planning and Public Health Use Tokyo's weather data to enhance urban planning and public health initiatives, mitigating heat islands, reducing flood risks, and improving residents' quality of life.

Acknowledgements Special thanks to the Japan Meteorological Agency for providing this valuable data. When using this data, please attribute it as follows:

出典：気象庁ホームページ　https://www.jma.go.jp/jma/kishou/info/coment.html

In 2024, the average air temperature in Japan's capital reached around 17.6 degrees Celsius. Tokyo's annual mean air temperature increased by four degrees Celsius since 1900, showing the progress of global warming. Weather in Tokyo Tokyo lies in the humid subtropical climate zone. It is affected by the monsoon circulation and has mild, sunny winters and hot, humid, and rainy summers. In most of Japan, the rainy season lasts from early June to mid-July. Furthermore, heavy rainfall is often caused by typhoons, which develop over the Pacific Ocean and regularly approach the archipelago between July and October. In recent years, the Kanto region, including Tokyo Prefecture, was approached by at least two typhoons each year. Since the winters are rather mild in Tokyo, the capital city does not often see snowfall and the snow rarely remains on the ground for more than a few days. Effects of global warming in Japan The increasing air temperature is one of the main consequences of global warming. Other effects are increased flooding frequency and a rise in sea levels due to melting ice caps. Global warming has already influenced Japan's climate in recent years, resulting in more frequent heat waves as well as increased annual rainfall. These weather changes can intensify natural disasters such as typhoons and inhibit the growth of crops. To counter global warming, Japan aims to reduce its greenhouse gas emissions by increasing its renewable and nuclear energy share.

This is a spectral dataset of natural objects and daylights collected in Japan.

We collected 359 natural objects and measured the reflectance of all objects and the transmittance of 75 leaves. We also measured daylights from dawn till dusk on four different days using a white plate placed (i) under the direct sun and (ii) under the casted shadow (in total 359 measurements). We also separately measured daylights at five different locations (including a sports ground, a space between tall buildings and a forest) with minimum time intervals to reveal the influence of surrounding environments on the spectral composition of daylights reaching the ground (in total 118 measurements).

Dataset contains following Excel spread sheets and csv files:

(A) Surface properties of natural objects

(A-1) Reflectance_ver1-2.xlsx and .csv

(A-2) Transmittance_FrontSideUp_ver1-2.xlsx and .csv

(A-2) Transmittance_BackSideUp_ver1-2.xlsx and .csv

(B) Daylight measurements

(B-1) Daylight_TimeLapse_v1-2.xlsx and .csv

(B-2) Daylight_DifferentLocations_v1-2.xlsx and .csv

Data description

(A) Surface properties

(A-1) Reflectance_ver1-2.xlsx and .csv

This file contains surface spectral reflectance data (380 - 780 nm, 5 nm step) of 359 natural objects, including 200 flowers, 113 leaves, 23 fruits, 6 vegetables, 8 barks, and 9 stones measured by a spectrophotometer (SR-2A, Topcon, Tokyo, Japan). Photos of all samples are included in the .xlsx file.

For the analysis presented in the paper, we identified reflectance pairs that have a Pearson’s correlation coefficient across 401 spectral channels of more than 0.999 and removed one of reflectances from each pair. The column 'Used in analysis' indicates whether or not each sample is used for the analysis (TRUE indicates used and FALSE indicate not used).

At the time of collection, we noted the scientific names of flowers, leaves and barks from a name board provided by the Tokyo Institute of Technology in which samples are collected. If not available, we used a smartphone software which automatically identifies the scientific name from an input image (PictureThis - Plant Identifier developed by Glority Global Group Ltd.). The names of 2 flowers and 9 stones whose name could not be identified through either method were left blank.

(A-2) Transmittance_FrontSideUp_v1-2.xlsx and .csv

This file contains surface spectral transmittance data (380 - 780 nm, 5 nm step) for 75 leaves measured by a spectrophotometer (SR-2A, Topcon, Tokyo, Japan). Photos of all samples are included in the .xlsx file.

For this data, the transmittance was measured with the front-side of leaves up (the light was transmitted from the back side of the leaves). This is the data presented in the associated article.

(A-3) Transmittance_BackSideUp_v1-2.xlsx and .csv

Spectral transmittance data of the same leaves presented in (A-2).

For this data, the transmittance was measured with the back-side of leaves up (the light was transmitted from the front side of the leaves).

(B) Daylight measurements

(B-1) Daylight_TimeLapse_ver1-2.xlsx and .csv

This file contains daylight spectra from sunrise to sunset on four different days (2013/11/20, 2013/12/24, 2014/07/03 and 2014/10/27) measured by a spectrophotometer (SR-LEDW, Topcon, Tokyo, Japan) with a wavelength range from 380 nm to 780 nm with 1 nm step. We measured the reflected light from the white calibration plate placed either under a direct sunlight or under a casted shadow.

The column 'Cloud cover' provides visual estimate of percentage of cloud cover across the sky at the time of each measurement. The column 'Red lamp' indicates whether an aircraft warning lamp at the measurement site was on (circle) or off (blank).

(B-2) Daylight_DifferentLocations_ver1-2.xlsx and .csv

This file includes daylight spectra measured at five different sites within the Suzukakedai Campus of Tokyo Institute of Technology with minimum time gap on 2014/07/08, using a spectroradiometer (IM-1000, Topcon) from 380 nm to 780 nm with 1 nm step. The instrument was oriented either towards the sun or towards the zenith sky. When the instrument was oriented to the sun, we measured spectra in two ways: (i) one using a black cylinder covering the photodetector and (ii) the other without using a cylinder.

The column 'Cylinder' indicates whether the black cylinder was used (circle) or not (cross). The column 'Cloud cover' shows the visual estimate of percentage of cloud cover at the time of each measurement. The column 'Sun hidden in clouds' denotes whether the measurement was taken when the sun was covered by clouds (circle) or not (blank).

Fayl Faylın tarixçəsi Faylın istifadəsi Faylın qlobal istifadəsi MetaməlumatlarSınaq göstərişi ölçüsü 800 533 piksel Dig

Temperature profile data were collected using bathythermograph (BT/XBT) casts from PACIFIC SUNSHINE and other platforms in the Pacific Ocean from January 9, 1986 to April 27, 1986. Data were submitted by Scripps Institution of Oceanography as part of the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project. Data were processed by NODC to the NODC standard Universal Bathythermograph Output (UBT) format. Full BT descriptions are available at http://www.nodc.noaa.gov/General/NODC-Archive/bt.html.

The UBT format contains temperature-depth profile data obtained using expendable bathythermograph (XBT) instruments. Cruise information, position, date and time were reported for each observation. The data record was comprised of pairs of temperature-depth values. Unlike the MBT Data File, in which temperature values were recorded at uniform 5 m intervals, the XBT data files contained temperature values at non-uniform depths. These depths were recorded at the minimum number of points ("inflection points") required to accurately define the temperature curve. Standard XBTs can obtain profiles to depths of either 450 or 760 m. With special instruments, measurements can be obtained to 1830 m.