Data Bundles & Variables

Complete reference for every Spire Weather data Bundle and the variables it contains. Bundles group related weather variables by use case, and multiple bundles can be requested in a single API call using the bundles query parameter.

Each bundle table lists the field, the GRIB2 shortName you will see in file products, the JSON key returned by the point-style APIs, the vertical level and the unit. A dash (—) means the field is not delivered through that channel. Default units are SI Units; request US Units with unit_system=us (Celsius, hPa, mph) or unit_system=us-f (Fahrenheit). See the Units Reference for details.

Products and their bundles¶

Historical Weather Data Bundles¶

Historical bundles are available through the Archive API (/archive/route). They provide reanalysis and hindcast data for past periods.

Core Bundle (Historical)¶

Standard surface-level meteorological variables for general-purpose historical analysis.

Agricultural Bundle (Historical)¶

Soil and surface energy variables for agricultural and land-surface applications.

Maritime Bundle (Historical)¶

Ocean surface and sea-state variables for marine and offshore historical analysis.

Maritime Wave Bundle (Historical)¶

Decomposed wind wave and swell components for detailed sea-state analysis.

Maritime Swell Wave Bundle (Historical)¶

Individual swell partitions for resolving distinct swell systems arriving from different origins.

Precipitation Bundle (Historical)¶

Detailed precipitation type and accumulation fields.

Wind Energy Bundle (Historical)¶

Hub-height wind variables for wind power assessment.

Solar Energy Bundle (Historical)¶

Radiation budget variables for solar resource assessment.

Thunderstorm Bundle (Historical)¶

Convective instability indices for severe weather analysis.

Current Weather Conditions (cwc)¶

Current conditions represent the latest analysis of the atmospheric state, updated every hour. Files are named cwc.{date}.tHHz.0p027.basic.{region}.grib2 (one per region and hour, about 3 km grid spacing) and are listed at /current/weather/file; point values come from /current/weather/point.

Basic Bundle (basic, Current Conditions)¶

Available at: /current/weather/file, /current/weather/point.

Global Weather Forecast Bundles (sof-d)¶

Global forecast bundles are the primary offering for forward-looking weather data. Files are named sof-d.{date}.tHHz.0p125.{bundle}.{region}.fHHH.grib2 (0.125°, about 14 km). They are served through the file, point, route, profile and WMS endpoints (availability varies by Bundle, see the matrix at the end of this page). Lead Time extends up to 15 days depending on subscription.

Every point-style response also carries the model terrain height of the requested location as location.coordinates.elevation (listed in meta.units as orography, m).

Basic Bundle (basic)¶

Standard surface-level meteorological variables for general-purpose forecasting.

Available at: file, point, route, profile, WMS endpoints.

Basic Accumulation Bundle (basic-accumulation)¶

Windowed precipitation accumulations for event-based analysis. This is an opt-in Bundle.

Available at: point endpoint only.

Maritime Bundle (maritime)¶

Ocean surface and sea-state forecast variables.

Available at: file, point, route, WMS endpoints.

Maritime Atmospheric Bundle (maritime-atmos)¶

Elevated wind variables relevant to vessel operations and offshore platforms.

Available at: file, point, route, WMS endpoints.

Maritime Waves Bundle (maritime-wave)¶

Decomposed wind wave and swell components for detailed sea-state forecasting.

Available at: file, point, route, WMS endpoints.

Maritime Waves Extended Bundle (maritime-wave-ext)¶

Additional wave statistics for advanced maritime applications.

Available at: file, point, route, WMS endpoints.

Thunderstorm Bundle (thunderstorm)¶

Convective instability and severe weather diagnostics.

Available at: file, point, WMS endpoints.

Upper Air Bundle (upper-air)¶

Three-dimensional atmospheric fields on isobaric (pressure) levels. File products only.

Available isobaric levels (hPa): 1000, 950, 925, 900, 850, 800, 700, 600, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 20, 15, 10, 7, 5, 3, 2, 1.

Available at: file, WMS endpoints only.

Aviation Bundle (aviation)¶

Flight-level fields for aviation weather decision support. Levels are heights above mean sea level corresponding to flight levels. File products only.

Flight levels FL100 to FL450 correspond to 10,000 to 45,000 feet (3,048 to 13,716 m) above MSL; icing potential starts at FL010 (305 m).

Available at: file endpoint only.

Agricultural Bundle (agricultural)¶

Soil and surface energy balance variables for agricultural forecasting.

Available at: file, point, route endpoints.

Clouds Bundle (clouds)¶

Cloud layer decomposition for visibility and radiation applications.

Available at: file, point, route, WMS endpoints (cloud ceiling not available at WMS).

Wind Energy Bundle (wind-energy)¶

Multi-height wind and air density variables for wind power forecasting.

Available at: file, point, route endpoints.

Solar Energy Bundle (solar-energy)¶

Radiation budget variables for solar power forecasting. All fields are accumulated since the start of the forecast (GRIB2 stepType: accum).

See Working with Accumulated Data Values for turning forecast-total accumulations into interval values.

Available at: file, point, route endpoints.

Solar Energy Accumulation Bundle (solar-energy-accumulation)¶

Windowed radiation accumulations for time-interval energy calculations. This is an opt-in Bundle.

All five radiation fields from the Solar Energy Bundle are provided in 1-hour, 3-hour and 6-hour windows. The JSON keys are the Solar Energy keys with the suffixes _1hr, _3hr and _6hr, for example surface_net_downward_shortwave_flux_1hr. All values are in J/m^2^.

Available at: point endpoint only.

Precipitation Bundle (precipitation)¶

Detailed precipitation type and accumulation fields for forecast applications.

The Point API collapses the four categorical masks into one text field, predominant_precipitation_type, with the values no_precipitation, rain, snow, freezing_rain and mixed/ice.

Available at: file, point, route, WMS endpoints.

Precipitation Accumulation Bundle (precipitation-accumulation)¶

Windowed snowfall accumulations for event-based analysis. This is an opt-in Bundle.

Available at: point endpoint only.

Optimized Point Forecast Bundles¶

Optimized point forecasts are post-processed, bias-corrected predictions at named locations (airports, ports, weather stations), updated every hour. They are available only through /forecast/point/optimized. The bundles parameter accepts basic, wind-energy and solar-energy; omitting it, or requesting basic, returns every variable available at the location. Hub-height winds and irradiance are only available at locations where they have been configured; elsewhere those bundles return 404 No data found.

Basic Bundle (basic, Optimized Point)¶

The location object of the response carries name, icao, wmo, unlocode and uuid where known, in addition to the coordinates.

Notes on individual fields:

• Heat index is returned only when the forecast temperature is hot; wind chill only when it is cold. Otherwise the values are null.

• Degree days compare the local daily mean temperature (average of the daily maximum and minimum) with 65 °F: the excess above 65 °F is the cooling degree days, the shortfall below it the heating degree days.

• 24-h maximum and minimum temperatures cover the remainder of the current calendar day, once in UTC and once in the station’s local time zone. At 18 UTC the UTC-day maximum is the maximum expected between 19:00 and 23:59 UTC.

• Probability of precipitation for 1, 3 and 6 hours refers to the window ending at the valid time; the 24-hour value refers to the remainder of the current UTC day.

• Ice amounts are frozen precipitation that is neither snow nor rain (sleet, ice pellets, freezing rain); _total fields accumulate from the start of the forecast.

• Cloud ceiling is only available at locations with a weather station and may lag the most recent issuance.

Wind Energy Bundle (wind-energy, Optimized Point)¶

Hub-height wind speed forecasts at multiple turbine-relevant heights, at configured wind-farm locations.

Solar Energy Bundle (solar-energy, Optimized Point)¶

Irradiance components for solar power forecasting, at configured solar-farm locations.

High-Resolution Forecast Bundles (SRFS, product=srfs)¶

High-resolution regional forecasts are produced by the Spire Regional Forecast System (SRFS). They provide 3 km spatial detail over the conus and europe regions, issued at 06 and 12 UTC with hourly lead times to 48 hours. File names follow the pattern:

srfs.{date}.{time}.03km.{bundle}.{region}.fHHHmMM.grib2

Example: srfs.20260911.t06z.03km.core-v2.europe.f006m00.grib2

Core Bundle (core, High-Res, legacy)¶

core is the original SRFS bundle and is kept for existing integrations only. It combines the surface fields of core-v2 with the eight isobaric levels of upper-air in one large file (about 100 MB per lead time for Europe) and receives no new fields. New integrations should use core-v2 for surface fields and upper-air for the isobaric levels.

Core-v2 Bundle (core-v2, High-Res)¶

The current SRFS surface bundle: 2 m and wind fields, pressure, cloud layers, boundary-layer height, precipitation totals and windows, precipitation type masks, reflectivity and shortwave radiation.

Upper-Air Bundle (upper-air, High-Res)¶

Geopotential height (gh), temperature (t), u/v wind (u, v), relative humidity (r), vertical velocity (w, Pa/s) and absolute vorticity (absv) on 1000, 925, 850, 700, 500, 300, 200 and 100 hPa.

Thunderstorm Bundle (thunderstorm, High-Res)¶

All variables of the global Thunderstorm Bundle plus one additional field:

Derived Bundle (derived, High-Res)¶

Computed diagnostic fields useful for pattern recognition and anomaly detection.

Available at: file endpoint only (all SRFS bundles).

AI Weather Forecast Bundles (SAIFS-WX, product=saifs-wx)¶

The Spire AI Weather Forecast is a machine-learning global ensemble forecast on a 0.25° grid (about 28 km), refreshed every 6 hours with 6-hourly lead times out to 15 days (f000 to f360), for the regions global, conus and europe. Files are named saifs-wx.{date}.tHHz.0p25.{bundle}.{region}.fHHH.grib2. Every field appears twice in a file: as the ensemble mean and as the ensemble spread (standard deviation across members), encoded as GRIB2 derived forecasts (productDefinitionTemplateNumber 2, derivedForecast 0 for the mean and 2 for the spread). The two anomaly fields of the derived bundle are provided as means only. The default file listing shows the hourly time-bundle slice (to 48 hours); request time_bundle=6_hourly_15day for the full range.

Available at: file endpoint only.

AI Sub-seasonal to Seasonal Bundles (SAIFS-S2S, product=saifs-s2s)¶

The Spire AI Sub-seasonal to Seasonal ensemble forecast is issued daily at 00 UTC on a 0.5° grid (about 55 km) for global, europe and north-america_central-america_caribbean, out to 46 days. Every field is a statistic over a period, not an instantaneous value. The surface and upper-air bundles deliver each field twice, as the ensemble mean and as the ensemble spread (standard deviation across members); the derived bundles deliver anomalies of the ensemble mean, and probabilities and percentiles describe the ensemble distribution. Each bundle name carries a temporal suffix:

• :daily files D001 to D046 hold 24-hour statistics for forecast days 1 to 46 (D001 covers 0--24 h).

• :weekly files W001 to W006 hold weekly statistics (for example W001 covers hours 72--240).

Files are named saifs-s2s.{date}.t00z.0p5.{bundle}.{region}.{Dnnn|Wnnn}.grib2; the bundle name in the file omits the suffix. Request bundles=surface:daily, surface:weekly, and so on; the suffix is required.

Surface (surface:daily, surface:weekly)¶

Upper Air (upper-air:daily, upper-air:weekly)¶

Derived (derived:daily, derived:weekly)¶

Anomalies of the ensemble mean for a subset of the surface fields: avg_2t, max_2t, min_2t, prmsl, ssrd, tp, avg_10ws and 100si. Each value is the ensemble mean for the period minus the model climatology for that time of year, in the same units as the surface bundle (a temperature anomaly of +1.5 means 1.5 K warmer than normal). The GRIB2 shortNames are the same as in the surface bundle; the files carry one message per field (8 in total) and no spread.

Derived Upper Air (derived-upper-air:daily, derived-upper-air:weekly)¶

Anomalies of the ensemble mean for a subset of the upper-air fields: the ensemble mean for the period minus the model climatology, in the units of the upper-air bundle. One message per field (13 in total), no spread.

Files are named saifs-s2s.{date}.t00z.0p5.derived-upper-air.{region}.{Dnnn|Wnnn}.grib2.

Probabilities (probabilities:daily, probabilities:weekly)¶

Categorical probabilities for each of the 12 surface fields relative to the model climatology, seven GRIB2 messages per field (GRIB2 template 9). Six carry a category index and category count in the lower and upper limit fields (probabilityType 10): the lowest and highest tercile (1 of 3, 3 of 3), quintile (1 of 5, 5 of 5) and decile (1 of 10, 10 of 10). The seventh (probabilityType 6) is the probability of the above-normal category.

Percentiles (percentiles:daily, percentiles:weekly)¶

Ensemble percentiles for each of the 12 surface fields (GRIB2 template 10): the 1st, 5th, 10th, 20th, 50th, 80th, 90th, 95th and 99th percentiles, nine messages per field. The percentileValue key is not populated in the files, so read the messages in file order.

Available at: file endpoint only.

Weather Regime Forecasts (product=saifs-s2s-regimes, product=saifs-wx-regimes)¶

Weather regime classifications derived from the SAIFS ensembles, delivered as one CSV per region and issuance: saifs-s2s-regimes.{date}.t00z.{CONUS|EUATL}.daily.csv and saifs-wx-regimes.{date}.tHHz.{CONUS|EUATL}.daily.csv. There is no bundle; list the files with /forecast/file?product=saifs-s2s-regimes.

Each valid day has one row per regime (including No Regime) whose probabilities sum to 100. The probabilities are the distribution of the daily 500 hPa weather regime across the ensemble members. The two products differ only in their source: saifs-wx-regimes is derived from the medium-range AI weather forecast (SAIFS-WX, issued every 6 hours), saifs-s2s-regimes from the sub-seasonal to seasonal ensemble (SAIFS-S2S, issued daily, out to 45 days).

Soil Moisture Insights (smi)¶

Soil Moisture Insights are a separate product family served by /soil-moisture/* and documented on their own site, developers.smi.spire.com. They use product names (d-mssm, d-essm, d-hssm and variants) rather than bundles; see the Soil Moisture page for the endpoints.

Lightning Density¶

Lightning density is a single-bundle product (core) of 5 km CONUS equal-area grids updated every 5 minutes, listed with bundles=core&resolutions=05km&periods=3600. See Lightning.

Bundle Availability by Endpoint¶

The tables below summarize which bundles are accessible at each API endpoint.

Historical Bundles¶

Current Conditions¶

Global Forecast Bundles (sof-d)¶

* Cloud ceiling height is not available at the WMS endpoint. The Profile API returns the basic fields on its own set of height levels; other bundles are not served there.

Optimized Point Forecast¶

Regional and AI Forecast Bundles (file API only)¶

Requesting Bundles¶

Specify one or more bundles using the bundles query parameter as a comma-separated list:

# Single bundle
curl -X GET \
  'https://api.wx.spire.com/forecast/point?lat=40.0&lon=-105.0&bundles=basic' \
  -H 'spire-api-key: YOUR_API_KEY'

# Multiple bundles
curl -X GET \
  'https://api.wx.spire.com/forecast/point?lat=40.0&lon=-105.0&bundles=basic,maritime,precipitation' \
  -H 'spire-api-key: YOUR_API_KEY'

# File products of another product
curl -X GET \
  'https://api.wx.spire.com/forecast/file?product=saifs-s2s&bundles=surface:weekly&regions=europe' \
  -H 'spire-api-key: YOUR_API_KEY'

For file-based downloads, bundles determine which GRIB2 or NetCDF files are available. See the File Naming Conventions for how the Bundle name appears in file names.