Comprehensive Heat Indices (CHI) Dataset (v1.0)

This dataset provides global (60°S to 75°N; 180°W to 180°E), high-resolution (0.1° × 0.1°), hourly historical data on 13 comprehensive heat stress indices for the period 1950–2024. Named the CHI (Comprehensive Heat Indices) dataset, the dataset provides the most comprehensive and detailed heat-stress climatology currently available, supporting studies of human thermal comfort, mortality risk, and climate adaptation across diverse environmental conditions.

The dataset is built around 13 key thermal comfort and stress indicators, including:

1. Mean Radiant Temperature (Tmrt)

2. Universal Thermal Climate Index (UTCI)

3. Wet-Bulb Globe Temperature (Twbg)

4. Natural Wet-Bulb Temperatures (Tnwb)

5. Indoor Wet-Bulb Temperature (Twb)

6. Natural Lethal Heat Stress Index (Lsin)

7. Indoor Lethal Heat Stress Index (Lsi)

8. Globe Temperature (Tg)

9. Heat Index (HI)

10. Apparent Temperature (AT)

11. Wind Chill (WC)

12. Humidex (Hu)

13. Normal Effective Temperature (NET)

These indices quantify how the human body experiences atmospheric conditions, incorporating the effects of air temperature, humidity, wind speed, solar radiation, and soil moisture—factors critical to assessing heat-related discomfort, workability, and mortality risk.

The dataset is derived from the ERA5 and ERA5-Land reanalyses from the European Centre for Medium-… (ECMWF). ERA5 provides hourly atmospheric data at a global scale using advanced data assimilation techniques, while ERA5-Land refines this output over land with a higher spatial resolution. Together, they underpin the CHI dataset's detailed global coverage (60°S to 75°N and 180°W to 180°E) and extended historical range.

CHI dataset improves upon earlier datasets by:

· Extended long-term coverage from 1950 to 2024

· Utilising 2 m wind speed instead of the standard 10 m, enhancing near-surface physiological relevance

· Computing solar zenith angles only during sunlit hours to avoid radiation-related index errors

· Providing both indoor and outdoor variants of key indices (e.g., Lsi, Tw)

· Offering the first global hourly dataset for the empirical, mortality-based lethal heat stress index (Ls)

The dataset is particularly relevant for applications in climate-health research, occupational heat risk, and climate adaptation, especially in vulnerable regions such as the Middle East, South Asia, and sub-Saharan Africa.

The dataset currently covers from 00:00 UTC on January 2, 1950, to 23:00 UTC on December 31, 2024. The dataset is produced by the Climate Change Center at King Abdullah University of… (KAUST) in collaboration with international researchers.

Data Download Link and User Guide to Access Data

The CHI dataset is available for public access and download via Globus, hosted by the KAUST (King Abdullah University of…) Data Repository – Datawaha. To access the data, the user should read the following document:

'User-Guide-to-Access-CHI-Da…'

For further important details, e.g., metadata, the user should read the following document:

'CHI-Dataset_Description'

Code

Heat stress indices in the CHI dataset were calculated using the thermofeel Python library (Brimicombe et al., 2022) and additional Python code developed by Kong et al. (2022). We integrated and adapted both codes according to our requirements. The modified and integrated version of these codes is available for download and further use from the GitHub repository at this link.

Cite Data: Malik, Abdul; Masabathini, Sateesh; Ahmed Shaikh, Mohsin; Kong, Qinqin; Usman, Muhammad; Prasad Dasari, Hari; et al. (2025). Comprehensive Heat Indices (CHI) Dataset (v1.0). figshare. Dataset. https://doi.org/10.6084/m9.…

License

ERA5-CHI (v1.0) © [Abdul Malik (KAUST)], 2025; Licensed underCreative Commons Attributio…; Source data: ERA5 reanalysis (©ECMWF, Copernicus Climate Change S…). Contains modified Copernicus Climate Change Service information [2025]. Neither the European Commission nor ECMWF is responsible for any use of the information it contains.

For license, read LICENSE.txt