Berkeley Earth¶
Berkeley Earth Land/Ocean Surface Temperature
Available
Current status
Since Q2 2025 the 0.25° high-resolution product (Berkeley Earth Surface Temperature – High-Resolution, BEST-HR) has been the operational record and is updated monthly; the long-standing 1° products (Land_and_Ocean_, Complete_ and the daily land files) are no longer updated. The high-resolution product is still labelled "PRELIMINARY DATA", and its description paper has been in open review at ESSD since September 2026.
At a glance¶
| Item | Details |
|---|---|
| Section | Atmosphere › Surface temperature |
| Type | Observation-based analysis |
| Domains | Atmosphere, Ocean |
| Provider | Berkeley Earth (independent U.S. non-profit research organization) |
| Period | 1850-01 ~ present |
| Coverage | Global |
| Horizontal resolution | High-resolution (current) product: 0.25° × 0.25° latitude–longitude grid (full-resolution files on request or from the Zenodo archive); 1° × 1° and 5° × 5° latitude–longitude grids available for direct download. Old product (no longer updated): 1° × 1° latitude–longitude grid and Equal Area grid |
| Vertical resolution | Single surface level (land surface air temperature blended with sea surface temperature over the ocean) |
| Temporal resolution | Monthly mean anomalies (the old product also has experimental daily land TAVG, TMAX and TMIN from 1880, no longer updated) |
| Update frequency | Monthly (high-resolution product). The old 1° product has not been updated since Q2 2025 |
| Licence | Creative Commons BY-NC 4.0 International (non-commercial use only) — contact Berkeley Earth for commercial licensing; attribution required |
| Account required | No |
Note on period: Global land + ocean TAVG starts in 1850, land-only TAVG in 1750, and high-resolution land TMAX and TMIN in 1850. When checked on 2026-10-12, the headers of the high-resolution global monthly files gave analysis run dates of 2026-09-11 (land) and 2026-08-13 (ocean); the last row (latest month) was not checked directly. The old 1° product was last run on 2025-01-04 and has not been updated since.
How to read the resolution
- Horizontal resolution lists both the native model grid and the grid you download, as given in the official documentation. The same dataset can come on different grids from different providers or products, so check the grid of your downloaded file.
- Grid spacing is not the effective resolution. A provided grid that is finer than the native one carries no extra information.
- Intervals and whether a value is instantaneous, mean or accumulated differ between variables — see 'Available variables' below.
- The 'provided resolution' in lists and the comparison table is a simplified km/degree value for quick comparison. Use this page for exact values.
Overview¶
A global surface temperature record from Berkeley Earth, an independent U.S. non-profit, combining air temperatures from about 58,000 land stations with HadSST4 sea surface temperatures from 1850 onward. Its hallmarks are a statistical homogenization that splits station records at discontinuities ("scalpel") and Kriging interpolation; the land record extends back to 1750. Since 2025 the flagship product is the 0.25° high-resolution record built with regression Kriging on physically informed predictors, with anomalies relative to 1951–1980. The gridded files include a monthly climatology, so absolute temperatures can be reconstructed.
What changes with the successor¶
Berkeley Earth Land/Ocean → Berkeley Earth BEST-HR¶
Transition: 2025 Q2
From Q2 2025 the 0.25° high-resolution product became the operational record and the 1° time series and gridded products stopped updating. The description paper (in review at ESSD) presents it as version 2 of the Berkeley Earth surface temperature record.
| Aspect | Berkeley Earth Land/Ocean | Berkeley Earth BEST-HR |
|---|---|---|
| Horizontal resolution | 1° × 1° latitude–longitude grid and Equal Area grid | 0.25° × 0.25° (public files at 1° and 5°; 0.25° on request or from Zenodo) |
| Interpolation method | Kriging | Regression Kriging with physically informed predictors; improved coastal blending |
| Ocean input | Reinterpolated HadSST4 (HadSST3 at the time of the original paper) | HadSST4, with spatial detail improved using ORAS5 ocean reanalysis predictors |
| Treatment under sea ice | Two versions — extrapolation from land air temperatures (default) or from water temperatures (Alternate) | Single approach: extrapolation from land air temperatures where ice is present |
| Uncertainty | 95% uncertainty in the time series files | 50-member ensemble added (time series and 1° grids) |
| Updates and status | Last run January 2025, no longer updated / peer reviewed in ESSD (2020) | Updated monthly / preliminary data; description paper in review at ESSD (since September 2026) |
| Daily data | Experimental daily land TAVG, TMAX and TMIN (from 1880) | No daily data in the high-resolution product (monthly only) |
Things to watch when switching
- Do not splice values from the two products into one series; recompute the full period with a single product.
- File names, URLs and variable layout have changed, so automated download scripts need updating.
- Daily data exist only in the discontinued old product, so recent periods require another dataset.
Sources: Berkeley Earth data page · Rohde et al. (2026, in review at ESSD) BEST-HR paper
Available variables¶
Variable names from the high-resolution gridded NetCDF files (per the README). Variable names in the old 1° product files were not checked directly this time.
Time-stamp convention — instantaneous, mean or accumulated? — click to show
All gridded values and time series are monthly mean temperature anomalies (°C) relative to the January 1951 – December 1980 average. Times in the high-resolution gridded files are decimal years, "each value corresponding to the midpoint of the respective month" (e.g. 1981.125 = February 1981).
climatologyin the gridded files is the estimated true surface temperature (°C) for each calendar month over 1951–1980 (12 values). Add the climatology for the same month to thetemperatureanomaly to get absolute temperature.- In the high-resolution grids, a value is reported as NaN where observations provide less than a 20% constraint on the anomaly.
- The 'annual' column in the global text files is a 12-month moving average centred on that month (e.g. the January–December 1950 mean appears in the June 1950 row). The five-, ten- and twenty-year columns are also centred moving averages.
- Where sea ice is present, anomalies are extrapolated from land air temperatures; where it is absent, from ocean temperatures (sea ice extent from HadISST v2). The old product also offered an 'Alternate' version that extrapolates from water temperatures under sea ice.
- The data are preliminary, so past values may change without notice at each monthly update.
Source: Berkeley Earth High-Resolution Gridded README / Global_TAVG_monthly.txt header
instantaneous mean accumulated maximum minimum static — instantaneous: value at the time stamp · mean/accumulated/maximum/minimum: over the indicated interval · static: does not change with time
High-resolution grids (NetCDF, 0.25°, 1°, 5°)¶
| Variable | Short name | Units | Time convention | Notes |
|---|---|---|---|---|
| Surface air temperature anomaly | temperature |
°C, relative to 1951–1980 | Monthly mean | |
| Monthly climatology (absolute temperature) | climatology |
°C | Monthly mean | Mean of each calendar month over 1951–1980; 12 values (January–December), not tied to a specific year |
| Land fraction | land_mask |
0–1 | static |
Summary time series (text)¶
| Variable | Short name | Units | Time convention | Notes |
|---|---|---|---|---|
| Global land + ocean TAVG anomaly with 95% uncertainty | - | °C | Monthly mean | Global_TAVG_monthly.txt |
| Land TAVG, TMAX and TMIN anomalies | - | °C | Monthly mean | Land_TAVG/TMAX/TMIN_monthly.txt |
| 50-member ensemble time series | - | °C | Monthly mean | *_ensemble.txt |
| Annual mean anomaly | - | °C | Annual mean | *_annual.txt |
Old product daily land data (experimental, no longer updated)¶
| Variable | Short name | Units | Time convention | Notes |
|---|---|---|---|---|
| Daily mean temperature anomaly | - | °C | Daily mean | Complete_TAVG_Daily_* |
| Daily maximum temperature anomaly | - | °C | Daily maximum | Complete_TMAX_Daily_* |
| Daily minimum temperature anomaly | - | °C | Daily minimum | Complete_TMIN_Daily_* |
The full variable list is in the official documentation.
How to get the data¶
- Berkeley Earth data page — HTTPS (web / wget / curl) No login needed
- Lists the high-resolution global and land time series and 1° and 5° gridded files (storage.googleapis.com/berkeley-earth-temperature-hr/), the old 1° products (no longer updated) and station data. The full 0.25° grids and high-resolution country and city series are provided through a request form.
- High-resolution 1° grid (global TAVG) — HTTPS (about 400 MB) No login needed
- The 5° grid is Global_TAVG_Gridded_5deg.nc (about 8 MB) in the same folder.
- Zenodo archive (April 2026 release, includes 0.25°) — HTTPS (about 55 GB, 21 files) No login needed
- Contains monthly, annual and ensemble time series for global TAVG and land TAVG/TMAX/TMIN, 1° ensemble NetCDF files and 0.25° gridded NetCDF files. As a frozen release it suits reproducible publications; get the latest months from the data page files.
- Old 1° product (no longer updated, January 2025 run) — HTTPS (about 400 MB) No login needed
- The Equal Area version (Land_and_Ocean_EqualArea.nc), the Alternate version (water temperatures under sea ice), land Complete_TAVG/TMAX/TMIN and the daily land files are in the same location.
Example code¶
Downloads the high-resolution 5° grid, reconstructs absolute temperature from anomaly plus climatology, and computes the area-weighted global mean anomaly.
import urllib.request
import numpy as np
import xarray as xr
url = ("https://storage.googleapis.com/berkeley-earth-temperature-hr/"
"global/gridded/Global_TAVG_Gridded_5deg.nc")
urllib.request.urlretrieve(url, "be_5deg.nc")
ds = xr.open_dataset("be_5deg.nc")
print(ds) # check dimension and coordinate names
anom = ds["temperature"] # °C, anomaly relative to 1951–1980
tdim = ds["time"].dims[0]
ydim, xdim = ds["latitude"].dims[0], ds["longitude"].dims[0]
t = ds["time"].values # decimal year, mid-month (e.g. 1981.125)
month = np.floor((t % 1) * 12).astype(int) # 0 = January … 11 = December
# Area-weighted global mean anomaly
w = np.cos(np.deg2rad(ds["latitude"]))
glob = anom.weighted(w).mean([ydim, xdim])
print(glob.isel({tdim: slice(-12, None)}).values.round(2))
# Absolute temperature = anomaly + climatology for the same month (last month shown)
clim = ds["climatology"]
mdim = [d for d in clim.dims if d not in (ydim, xdim)][0]
absolute_last = anom.isel({tdim: -1}) + clim.isel({mdim: month[-1]})
Practical tips¶
- The old 1° products (Land_and_Ocean_complete.txt, Land_and_Ocean_LatLong1.nc, etc.) have not been updated since Q2 2025. If your scripts still point to them, switch to the high-resolution files. The two products use different methods, so do not splice them into one series.
- The high-resolution product is labelled "PRELIMINARY DATA - SUBJECT TO CHANGE WITHOUT NOTICE - NOT YET PEER REVIEWED". In papers, record the download date or use the frozen Zenodo release (DOI).
- The CC BY-NC 4.0 licence means commercial use, including paid services and products, needs permission from Berkeley Earth.
- The ocean component is a reinterpolation of HadSST4, the same ocean input as HadCRUT5, so agreement between the two is not an independent confirmation.
- Anomalies are relative to 1951–1980 (as in GISTEMP), whereas HadCRUT5 uses 1961–1990. Align the baselines before comparing.
- The high-resolution gridded files carry no uncertainty information. Use the 95% ranges in the text time series or the 50-member ensemble files instead.
- A 0.25° grid can be finer than the station network. In data-sparse regions and early decades, small-scale structure may come from the statistical predictors rather than observations, so interpret it with care.
Notices and change history¶
2026-09-01 · Info · BEST-HR description paper opens for public discussion in ESSD
The paper describing the 0.25° high-resolution record is in open review in ESSD Discussions. It presents 58,311 land stations, HadSST4 with ORAS5 predictors, regression Kriging and a new uncertainty ensemble, and states that monthly updates will be posted mainly on the Berkeley Earth website.
2026-05-28 · Info · Berkeley Earth High Resolution Dataset - April 2026 archived on Zenodo (DOI issued)
A frozen release with global TAVG and land TAVG, TMAX and TMIN time series, 50-member ensembles and 1°/0.25° grids was published on Zenodo under CC BY-NC 4.0.
2026-01-14 · Info · Global Temperature Report for 2025
Berkeley Earth released its annual report for 2025, based on observations in global archives as of early January 2026; calculations may be revised as late data arrive. National averages were computed from the high-resolution gridded data.
2025-04 (day not given) · Warning · 1° time series and gridded products no longer updated; replaced by the high-resolution product
The data page states that "Effective Q2 2025 the 1°x1° resolution time series and gridded products below are no longer being updated" (Land_and_Ocean_, Complete_, including daily data; no exact date given). Use the high-resolution files for current data.
References for your paper¶
Double-check before using in a paper
The citations below were compiled by the maintainer and may contain errors. Always double-check DOIs, authors, years and access-date formats against the provider's official dataset page and your journal's guidelines.
Dataset citation¶
Zenodo dataset DOI (high-resolution, April 2026 release) — DOI 10.5281/zenodo.20428381
Rohde, R., Hausfather, Z., Calvert, B. (2026): Berkeley Earth High Resolution Dataset - April 2026. Zenodo. https://doi.org/10.5281/zenodo.20428381
Show BibTeX
Reference papers¶
Berkeley Earth Land/Ocean Temperature Record paper (old 1° product) — DOI 10.5194/essd-12-3469-2020
Rohde, R. A., Hausfather, Z. (2020): The Berkeley Earth Land/Ocean Temperature Record. Earth System Science Data, 12(4), 3469–3479.
Show BibTeX
High-resolution product (BEST-HR) description paper — ESSD preprint in review — DOI 10.5194/essd-2026-412
Rohde, R. A., Calvert, B., Hausfather, Z. (2026): Berkeley Earth Surface Temperature – High-Resolution (BEST-HR): a 0.25° Global Gridded Temperature Data Set for Climate Monitoring. Earth System Science Data Discussions [preprint].
Show BibTeX
@article{rohde2026besthr,
author = {Rohde, Robert A. and Calvert, Bruce and Hausfather, Zeke},
title = {{Berkeley Earth} Surface Temperature -- High-Resolution ({BEST-HR}): a 0.25{\textdegree} Global Gridded Temperature Data Set for Climate Monitoring},
journal = {Earth System Science Data Discussions},
year = {2026},
note = {preprint, in review},
doi = {10.5194/essd-2026-412}
}
Acknowledgements¶
"Attribution under CC BY-NC terms should be given to Berkeley Earth", with a reference to www.berkeleyearth.org where possible (Berkeley Earth data page). The old 1° product files cite Rohde & Hausfather (2020). While the high-resolution description paper is in review, cite both the preprint and the Zenodo release DOI.
If this page helped, please acknowledge the Korean Climate Data Navigator
Please add the sentence below to the Acknowledgements of your paper.