Data

Index datasets

A catalogue of the climate hazard index datasets earthflux produces, and plans to produce, from public data sources. Each entry lists its inputs and the sources it can be generated from; live previews show real calculated values for the products published so far.

PreviewPreviews cover SPI and SPEI only, calculated from NOAA nClimGrid on a sampled grid (about 0.33°), not the full-resolution product. Everything else in the catalogue is planned. Full-grid Zarr and NetCDF downloads are not published; the addresses below are examples, not live links.

Dataset catalogue

2 live previews41 planned datasetsPreview: values are browsable below. Planned: on the roadmap, not yet published.

Drought

IndexInputsDatasets by source
Standardized Precipitation IndexSPIPrecipitation
  • nClimGrid monthly: Preview
  • ERA5 (NSF NCAR curated): Planned
  • CMIP6 projections: Planned
Standardized Precipitation Evapotranspiration IndexSPEIPrecipitation, PET
  • nClimGrid monthly: Preview
  • ERA5 (NSF NCAR curated): Planned
  • CMIP6 projections: Planned
Self-calibrated Palmer Drought Severity IndexscPDSIPrecipitation, PET, available water capacity
  • nClimGrid monthly: Planned
  • ERA5 (NSF NCAR curated): Planned
Palmer Drought Severity Index familyPDSI, PHDI, PMDI, Z-IndexPrecipitation, PET, available water capacity
  • nClimGrid monthly: Planned
  • ERA5 (NSF NCAR curated): Planned
Evaporative Demand Drought IndexEDDIReference evapotranspiration
  • ERA5 (NSF NCAR curated): Planned
Potential evapotranspiration, ThornthwaitePETMean temperature, latitude
  • nClimGrid monthly: Planned
  • ERA5 (NSF NCAR curated): Planned
Potential evapotranspiration, HargreavesPETMin and max temperature, latitude
  • nClimGrid monthly: Planned
  • ERA5 (NSF NCAR curated): Planned
Reference evapotranspiration, Penman–MonteithEToTemperature, humidity, radiation, wind
  • ERA5 (NSF NCAR curated): Planned
Percentage of normal precipitationPNPPrecipitation
  • nClimGrid monthly: Planned
  • ERA5 (NSF NCAR curated): Planned
Precipitation Concentration IndexPCIDaily precipitation
  • nClimGrid daily: Planned
  • ERA5 (NSF NCAR curated): Planned

Fire

IndexInputsDatasets by source
Keetch–Byram Drought IndexKBDIDaily max temperature, daily precipitation, mean annual precipitation
  • nClimGrid daily: Planned
  • ERA5 (NSF NCAR curated): Planned
Canadian Forest Fire Weather Index SystemFFMC, DMC, DC, ISI, BUI, FWI, DSRNoon temperature, relative humidity, wind, 24-hour precipitation
  • ERA5 (NSF NCAR curated): Planned
Fosberg Fire Weather IndexFFWITemperature, relative humidity, wind
  • ERA5 (NSF NCAR curated): Planned
Hot-Dry-Windy IndexHDWTemperature, humidity and wind on pressure levels
  • ERA5 (NSF NCAR curated): Planned
Haines IndexHainesTemperature and dew point at two pressure levels
  • ERA5 (NSF NCAR curated): Planned

Flood

IndexInputsDatasets by source
Effective precipitationPEDaily precipitation
  • nClimGrid daily: Planned
  • ERA5 (NSF NCAR curated): Planned
Effective Drought IndexEDIDaily precipitation
  • nClimGrid daily: Planned
  • ERA5 (NSF NCAR curated): Planned
Flood IndexI_FDaily precipitation
  • nClimGrid daily: Planned
  • ERA5 (NSF NCAR curated): Planned
Antecedent Precipitation IndexAPIDaily precipitation
  • nClimGrid daily: Planned
  • ERA5 (NSF NCAR curated): Planned

Energy

IndexInputsDatasets by source
Heating, cooling and energy degree daysHDD, CDD, EDDDaily mean temperature, heating and cooling base temperatures
  • nClimGrid daily: Planned
  • ERA5 (NSF NCAR curated): Planned
Hub-height wind speedWind profileWind speed, reference and hub heights, shear method
  • ERA5 (NSF NCAR curated): Planned
Wind capacity factorWind CFHub-height wind speed, power curve, air density
  • ERA5 (NSF NCAR curated): Planned
PV capacity factor, temperature-deratedPV CFSurface solar radiation as a mean flux (W m⁻²), 2 m temperature, 10 m wind
  • ERA5 (NSF NCAR curated): Planned
Standardized Renewable Energy Production IndexSREPIRenewable production proxy or capacity factor, timescales, calibration years
  • ERA5 (NSF NCAR curated): Planned
Standardized demand indexDemand indexEnergy demand proxy, timescales, calibration years
  • nClimGrid daily: Planned
  • ERA5 (NSF NCAR curated): Planned
Standardized Residual Load IndexSRLIResidual-load proxy (signed), timescales, calibration years
  • ERA5 (NSF NCAR curated): Planned

Preview viewer

Real SPI and SPEI values calculated from NOAA nClimGrid inputs, sampled at every 8th source grid cell for fast browsing. Gamma-distribution maps and location histories cover 1, 2, 3, 6, 9, 12, 24 and 36 months through August 2026. Other indices appear here as their datasets are published.

Index
Distribution
Time scale, in months

SPI-12, gamma

Loading

Loading index data

  • Extremely dry≤ −2.0
  • Severely dry−2.0 to −1.5
  • Moderately dry−1.5 to −1.0
  • Near normal−1.0 to 1.0
  • Moderately wet1.0 to 1.5
  • Very wet1.5 to 2.0
  • Extremely wet≥ 2.0
Demonstration sample: climate_indices example output on a reduced nClimGrid grid (about 0.67°), January 1991 to February 2017. Placeholder data, not for analysis.

Planned files for SPI-12, gamma, nClimGrid monthly

Each product is planned as a Zarr store for partial reads over HTTPS and a single NetCDF file. The intended coverage is the full 1/24° grid from January 1895.

Zarr store
https://data.earthflux.org/nclimgrid/monthly/nclimgrid_spi_gamma_12.zarr
NetCDF file
https://data.earthflux.org/nclimgrid/monthly/nclimgrid_spi_gamma_12.nc

Example paths and commands only. Do not use these addresses until the first products are published.

Python
# Read only the cells and months you need (no account or key required)
import xarray as xr

ds = xr.open_zarr(
    "https://data.earthflux.org/nclimgrid/monthly/nclimgrid_spi_gamma_12.zarr",
)
oklahoma_city = ds["spi_gamma_12"].sel(lat=35.47, lon=-97.52, method="nearest")
august_2011 = ds["spi_gamma_12"].sel(time="2011-08")
Command line
# Or copy the whole NetCDF file
curl -O https://data.earthflux.org/nclimgrid/monthly/nclimgrid_spi_gamma_12.nc

Input sources

  • nClimGrid monthly

    NOAA NCEI

    Contiguous US, about 5 km, 1895 to present. Precipitation, mean, min and max temperature. 596 by 1385 cells at 1/24°.

    s3://noaa-nclimgrid-monthly-pds

    7 catalogue datasets, 2 in preview

  • nClimGrid daily

    NOAA NCEI

    Contiguous US, about 5 km, 1951 to present. Precipitation, mean, min and max temperature.

    s3://noaa-nclimgrid-daily-pds

    8 catalogue datasets

  • ERA5 (NSF NCAR curated)

    ECMWF, curated by NSF NCAR

    Global, 0.25°, hourly. Precipitation, temperature, humidity, wind, radiation.

    s3://nsf-ncar-era5

    26 catalogue datasets

  • CMIP6 projections

    WCRP CMIP6

    Global, model grids, historical and future scenarios. Precipitation, temperature and more, by model.

    s3://cmip6-pds

    2 catalogue datasets

  • Your own data

    You

    Any grid or set of points with a time dimension. Map your variable names to precipitation and temperature.

    An s3:// path or a local file

How datasets are made

Inputs
Read from public open-data registries such as the AWS Registry of Open Data, or from your own Zarr or NetCDF files. Each dataset is tied to the source it was generated from.
Derived variables
Thornthwaite PET from mean temperature and latitude feeds SPEI and the Palmer indices on nClimGrid. Sources with humidity, wind and radiation also allow Penman–Monteith reference evapotranspiration, which EDDI needs.
Soil water
The Palmer indices also need available water capacity. nClimGrid doesn’t include it, and the source grid is still to be chosen.
Calibration
Set per index and source. The available gamma SPI and SPEI calculations use 1950 to 2010; future products may differ.
Validation and provenance
Each index’s evidence is summarized on the Indices page and recorded in VALIDATION.md. Published files will record the climate_indices software version and parameters in their metadata.
Attribution and updates
Datasets are attributed to their sources. Current previews derive from NOAA Monthly U.S. Climate Gridded Dataset (nClimGrid), Vose et al. 2014, doi:10.7289/V5SX6B56; these are modified data and are not endorsed by NOAA. A monthly refresh is planned, and recent nClimGrid inputs may be revised by NCEI.

Tools for the planned files

  • xarray in a notebook

    Open the Zarr store lazily and pull out a region, a month or a single location without downloading the rest.

  • xcube Viewer

    Serve the Zarr store with xcube and browse it on a map, with time navigation and point time series.

  • Panoply

    NASA's desktop viewer for NetCDF files. Good for quick maps and plots without writing code.