GISS Surface Temperature Analysis (GISTEMP v4)
The GISS Surface Temperature Analysis version 4 (GISTEMP v4) is an estimate of global surface temperature change. Graphs and tables are updated about the 10th of every month using current data files from NOAA GHCN v4 (meteorological stations) and ERSST v5 (ocean areas), combined as described in our publications Hansen et al. (2010) and Lenssen et al. (2024). These updated files incorporate reports for the previous month and also late reports and corrections for earlier months.
News and Updates
March 11, 2026: This webpage has been re-organized, and the data downloads formerly appended to the end of the page are now listed on a separate GISTEMP v4 data downloads page.
January 14, 2026: The 2025 annual surface temperature anomaly data were released today. NASA posted a short news release about the analysis.
November 14, 2025: The October GISTEMP analysis was posted today. The input GHCN v4 file is still lacking recent data from various countries; this affects all months starting with August 2025. We will indicate here when that problem has been resolved.
See the Release Dates Schedule for a schedule of the anticipated dates through the end of 2025 on which the monthly analysis should be posted.
See the GISTEMP News page for a list of NASA releases and other articles and features related to the GISTEMP analysis.
See the Updates to Analysis page for detailed update information about GISTEMP v4.
Background and History
The basic GISS temperature analysis scheme was defined in the late 1970s by James Hansen when a method of estimating global temperature change was needed for comparison with one-dimensional global climate models. The analysis method was fully documented in Hansen and Lebedeff (1987). Several papers describing updates to the analysis followed over the following decades, most recently that of Hansen et al. (2010), as well as the uncertainty quantification of Lenssen et al. (2019) and Lenssen et al. (2024).
For further details, please see the GISTEMP Background, History, and References pages. We also maintain a running record of modifications made to the analysis on our Updates to Analysis page.
Many questions about the GISTEMP analysis are already answered in the FAQ. If the FAQ does not answer your question, please address your inquiry to Dr. Reto Ruedy.
Source Code, Including Re-formatting Ocean Data
Programs used in the GISTEMP analysis and documentation on their use are available for download. The programs assume a Unix-like operating system and require familiarity with Python for installation and use.
Data Downloads
Monthly surface temperature anomaly data are available for download in several forms: plain-text tables of Land-Ocean Temperature Index (LOTI) deviations from the 1951-1980 means, plain-text tables of AIRS anomalies from the 2007-2016 means, netCDF data files on a regular 2°×2° regular grid, compressed Zarr (v3) data directories on a regular 2°×2° regular grid, and compressed basic subbox (SBBX) data on an equal-area grid. Example Fortran codes for working with the gridded data are also provided.
Uncertainty Analyses
Datasets and R source code, as well as documentation on their use, may be downloaded for the 2024 uncertainty ensemble and 2019 uncertainty quantification analyses by Lenssen et al.
Citation and Image Credits
When referencing the GISTEMP v4 data provided here, please cite both this webpage and also our most recent scholarly publication about the data. In citing the webpage, be sure to include the date of access.
- GISTEMP Team, 2026: GISS Surface Temperature Analysis (GISTEMP), version 4. NASA Goddard Institute for Space Studies. Dataset accessed 20YY-MM-DD at https://data.giss.nasa.gov/gistemp/.
- Lenssen, N., G.A. Schmidt, M. Hendrickson, P. Jacobs, M. Menne, and R. Ruedy, 2024: A GISTEMPv4 observational uncertainty ensemble. J. Geophys. Res. Atmos., 129, no. 17, e2023JD040179, doi:10.1029/2023JD040179.
An extensive Reference List is available for those wanting to explore past publications about the GISTEMP analysis and some of the input resources.
Graphics from these GISTEMP pages are subject to NASA Image and Media guidance. Per those guidelines, graphics you may create using the website tools here do not require permission for you to use elsewhere, but acknowledgment of their source should be given. Please credit "NASA's Goddard Institute for Space Studies" or, if space is limited, "NASA GISS/GISTEMP".
Contacts/Personnel
Scientific and technical questions about the GISTEMP analysis should be addressed to Dr. Reto Ruedy. Media inquiries should be addressed to Peter Jacobs at the Office of Communications at NASA's Goddard Space Flight Center.
Other researchers currently participating in the GISTEMP analysis include Michael Hendrickson and Dr. Nathan Lenssen.
The GISTEMP analysis was initiated by Dr. James E. Hansen, now retired. It is currently led by Dr. Gavin Schmidt.
Past members on the GISTEMP team have included Dr. Sergej Lebedeff, Dr. Helene Wilson, Jay Glascoe, Avraham Persin, Dr. Ken Lo, Maxwell Elling, Dr. Makiko Sato, Alexander Herron, and others. We also thank Nick Barnes et al. at the Clear Climate Code project for their contributions.
References
Please see the GISTEMP references page for citations to publications related to this research. Copies of many of our papers are available in the GISS publications database.
