GISS Surface Temperature Analysis (GISTEMP v4) (2024)

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 around the middle of every month using current data files from NOAA GHCNv4 (meteorological stations) and ERSST v5 (ocean areas), combined asdescribed in our publicationsHansen et al. (2010) andLenssen et al. (2019).These updated files incorporate reports for the previous month and also late reportsand corrections for earlier months.

News and Updates

Feb. 8, 2024:Three stations in Northern Canada were discovered to have a discontinuity in their records that is not present in the any other station in that area. This was reported to NOAA/NCEI and the reports after the discontinuity were removed.

Jan. 12, 2024:NASA has posted a news release 2023 annual global temperature anomaly.The NASA Earth Observatory website has also posted an explainer about causes of the record anomaly.

See theGISTEMP News page for a list of NASA releases and other articles and features related to the GISTEMP analysis.Announcements when our monthly updates are released are posted to the NASA/GISS Twitter feed.

See theUpdates to Analysis page for detailed update information about GISTEMP v4.

Contacts/Personnel

Before contacting us, please check if your question about the GISTEMP analysis is already answered inthe FAQ.

If the FAQ does not answer your question,please address your inquiry toDr. Reto Ruedy.

Other researchers currently participating in the GISTEMP analysis includeMichael Hendrickson,Maxwell Elling,Alexander Herron,Dr. Makiko Sato,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 includedDr. Sergej Lebedeff,Dr. Helene Wilson,Jay Glascoe,Avraham Persin,Dr. Ken Lo, and others.We also thank Nick Barnes et al. at the Clear Climate Code project for their contributions.

Citation

When referencing the GISTEMP v4 data provided here,please cite both this webpage and also our most recentscholarly publication about the data.In citing the webpage, be sure to include the date of access.

• GISTEMP Team, 2024: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. Schmidt, J. Hansen, M. Menne, A. Persin, R. Ruedy, and D. Zyss, 2019: Improvements in the GISTEMP uncertainty model. J. Geophys. Res. Atmos., 124, no. 12, 6307-6326, doi:10.1029/2018JD029522.

Graphics from these GISTEMP pages are subject to NASAImage and Media guidance.Per those guidelines, graphics you may create using the website tools here do not requirepermission 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".

Background, History and Updates

The basic GISS temperature analysis scheme was defined in the late 1970s by James Hansen when a methodof estimating global temperature change was needed for comparison with one-dimensional global climatemodels.The analysis method was fully documented inHansen and Lebedeff (1987).Several papers describing updates to the analysis followed over the following decades,most recently that ofHansen et al. (2010),as well as the uncertainty quantification of Lenssen et al. (2019).

For further details, please see the GISTEMPBackground,History, andReferences pages.We also maintain a running record of modifications made to the analysis on ourUpdates to Analysis page.

The GISTEMP analysis is updated regularly. Graphs and tables are posted around themiddle of every month using the latest GHCN and ERSST data. The update incorporates reportsfor the previous month as well as late reports and corrections for earlier months.

Source Code

Programs used in the GISTEMP analysis and documentation on their use areavailable for download.The programs assume a Unix-like operating system and require familiarity with Python for installation and use.

Tables of Global and Hemispheric Monthly Means and Zonal Annual Means

Combined Land-Surface Air and Sea-Surface Water Temperature Anomalies(Land-Ocean Temperature Index, L-OTI)

The following are plain-text files in tabular format of temperature anomalies, i.e. deviations from the corresponding 1951-1980 means.

• Global-mean monthly, seasonal, and annual means, 1880-present, updated through most recent month: TXT, CSV
• Northern Hemisphere-mean monthly, seasonal, and annual means, 1880-present, updated through most recent month: TXT, CSV
• Southern Hemisphere-mean monthly, seasonal, and annual means, 1880-present, updated through most recent month: TXT, CSV
• Zonal annual means, 1880-present, updated through most recent complete year: TXT, CSV

AIRS v6 and AIRS v7 Temperature Anomalies

The following tables show anomalies based on AIRS data vs. 2007-2016. Corresponding L-OTI anomaly data are also provided.

• Global-mean monthly, seasonal, and annual means, 2002-present, updated through most recent month: TXT, CSV
• Northern Hemisphere-mean monthly, seasonal, and annual means, 2002-present, updated through most recent month: TXT, CSV
• Southern Hemisphere-mean monthly, seasonal, and annual means, 2002-present, updated through most recent month: TXT, CSV
• Zonal annual means, 2002-present, updated through most recent complete year: TXT, CSV

Gridded Monthly Temperature Anomaly Data

Users interested in the entire gridded surface air temperature anomaly data maydownload netCDF files containing selected series on a regular 2°×2°grid or the basic SBBX binary files.

Compressed NetCDF Files (regular 2°×2° grid)

• Land-Ocean Temperature Index, ERSSTv5, 1200km smoothing (23 MB)
• Surface air temperature (no ocean data), 250km smoothing (9 MB)
• Land Mask on a 2°×2° grid

Compressed Zarr Directories (regular 2°×2° grid)

• Land-Ocean Temperature Index, ERSSTv5, 1200km smoothing (53 MB)
• Surface air temperature (no ocean data), 250km smoothing (27 MB)

Compressed Basic Subbox Grid Series (equal-area grid)

• Surface air temperature, 1200km smoothing - GISTEMP v4 (27 MB)
• Surface air temperature, 250km smoothing - GISTEMP v4 (9 MB)
• Sea surface air temperature (ERSSTv5), currently used (30 MB)
• Sea surface air temperature (ERSSTv4), used until July 2017 (30 MB)
• Sea surface air temperature (ERSSTv3b), used until June 2015 (30 MB)
• Sea surface air temperature (HadR2), used until Nov. 2012 (30 MB)

Also available are various FORTRAN programs and instructions to create (time series of) regular griddedanomaly maps from the basic files. Be sure to read the README file for discussion of the files' binaryformat.

• README.txt
• mkTsMap.f
• SBBX_to_nc.f
• SBBX_to_1x1.f
• SBBX_to_txt.f