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What you should know about this indicator

  • Temperature anomalies show how many degrees Celsius temperatures have changed compared to the 1861-1890 period. This baseline period is commonly used to highlight the changes in temperature since pre-industrial times, prior to major human impacts.
  • Temperature averages and anomalies are calculated over all land and ocean surfaces.
  • The data includes separate measurements for the Northern and Southern Hemispheres, which helps researchers analyze regional differences.
  • The global temperature anomaly is the average of both hemisphere measurements.
  • This data is based on the HadCRUT5 method. This method averages temperature measurements onto a fixed grid. If no data is available for a grid cell, it remains empty and adds extra uncertainty when calculating averages like the global mean.
  • Despite different approaches, HadCRUT5 and other methods show similar global temperature trends.

How is this data described by its producer?

The 1961-90 period is most often used as a baseline because it is the period recommended by the World Meteorological Organisation. In some cases other periods are used. For global average temperatures, an 1861-1890 period is sometimes used to show the warming since the "pre-industrial" period.

Global average temperature anomaly relative to 1861-1890
Difference in average land-sea surface temperature compared to the 1861-1890 mean, in degrees Celsius.
Source
Met Office Hadley Centre - HadCRUT5 (2026) – with major processing by Our World in Data
Last updated
August 21, 2026
Next expected update
October 2026
Date range
1850–2026
Unit
degrees Celsius

Sources and processing

This data is based on the following sources

Met Office Hadley Centre – HadCRUT5

The HadCRUT5 near surface temperature data set is produced by blending data from the CRUTEM5 surface air temperature dataset and the HadSST4 sea-surface temperature dataset.

Temperature anomalies are based on the HadCRUT5 near-surface temperature dataset as published by the Met Office Hadley Centre.

Retrieved on
August 21, 2026
Retrieved from
https://www.metoffice.gov.uk/hadobs/hadcrut5/
Citation
This is the citation of the original data obtained from the source, prior to any processing or adaptation by Our World in Data. To cite data downloaded from this page, please use the suggested citation given in Reuse This Work below.
Morice, C. P., Kennedy, J. J., Rayner, N. A., Winn, J. P., Hogan, E., Killick, R. E., et al. (2021). An updated assessment of near-surface temperature change from 1850: the HadCRUT5 data set. Journal of Geophysical Research: Atmospheres, 126, e2019JD032361. doi:10.1029/2019JD032361 (supporting information).

The HadCRUT5 near surface temperature data set is produced by blending data from the CRUTEM5 surface air temperature dataset and the HadSST4 sea-surface temperature dataset.

Temperature anomalies are based on the HadCRUT5 near-surface temperature dataset as published by the Met Office Hadley Centre.

Retrieved on
August 21, 2026
Retrieved from
https://www.metoffice.gov.uk/hadobs/hadcrut5/
Citation
This is the citation of the original data obtained from the source, prior to any processing or adaptation by Our World in Data. To cite data downloaded from this page, please use the suggested citation given in Reuse This Work below.
Morice, C. P., Kennedy, J. J., Rayner, N. A., Winn, J. P., Hogan, E., Killick, R. E., et al. (2021). An updated assessment of near-surface temperature change from 1850: the HadCRUT5 data set. Journal of Geophysical Research: Atmospheres, 126, e2019JD032361. doi:10.1029/2019JD032361 (supporting information).

How we process data at Our World in Data

All data and visualizations on Our World in Data rely on data sourced from one or several original data providers. Preparing this original data involves several processing steps. Depending on the data, this can include standardizing country names and world region definitions, converting units, calculating derived indicators such as per capita measures, as well as adding or adapting metadata such as the name or the description given to an indicator.

At the link below you can find a detailed description of the structure of our data pipeline, including links to all the code used to prepare data across Our World in Data.

Read about our data pipeline
Notes on our processing step for this indicator
  • We switch from using 1961-1990 to using 1861-1890 as our baseline to better show how temperatures have changed since pre-industrial times.
  • For each region, we calculate the mean temperature anomalies for 1961-1990 and for 1861-1890. The difference between these two means serves as the adjustment factor.
  • This factor is applied uniformly to both the temperature anomalies and the confidence intervals to ensure that both the central values and the associated uncertainty bounds are correctly shifted relative to the new 1861-1890 baseline.

Reuse this work

  • All data produced by third-party providers and made available by Our World in Data are subject to the license terms from the original providers. Our work would not be possible without the data providers we rely on, so we ask you to always cite them appropriately (see below). This is crucial to allow data providers to continue doing their work, enhancing, maintaining and updating valuable data.
  • All data, visualizations, and code produced by Our World in Data are completely open access under the Creative Commons BY license. You have the permission to use, distribute, and reproduce these in any medium, provided the source and authors are credited.

Citations

How to cite this page

To cite this page overall, including any descriptions, FAQs or explanations of the data authored by Our World in Data, please use the following citation:

“Data Page: Global average temperature anomaly relative to 1861-1890”, part of the following publication: Hannah Ritchie, Pablo Rosado, and Veronika Samborska (2024) - “Climate Change”. Data adapted from Met Office Hadley Centre. Retrieved from https://archive.ourworldindata.org/20260909-063824/grapher/temperature-anomaly.html [online resource] (archived on September 9, 2026).

How to cite this data

In-line citationIf you have limited space (e.g. in data visualizations), you can use this abbreviated in-line citation:

Met Office Hadley Centre - HadCRUT5 (2026) – with major processing by Our World in Data

Full citation

Met Office Hadley Centre - HadCRUT5 (2026) – with major processing by Our World in Data. “Global average temperature anomaly relative to 1861-1890” [dataset]. Met Office Hadley Centre, “HadCRUT5 HadCRUT.5.1.0.0” [original data]. Retrieved September 9, 2026 from https://archive.ourworldindata.org/20260909-063824/grapher/temperature-anomaly.html (archived on September 9, 2026).

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