Met Office Global 10 km forecasts in GribStream

GribStream now includes the Met Office Global Deterministic 10 km forecast. The first release focuses on six surface fields: air temperature, dew point, relative humidity, mean-sea-level pressure, and 10 metre wind speed and direction.

Current forecast availability

GribStream currently provides a rolling three-day window of forecast runs, measured by each run’s start time—not its forecast horizon. We’re filling remaining gaps, so coverage varies by dataset, parameter and run. Longer history is planned. Check coverage for your requested dates before relying on historical data.

That gives you another global forecast to query alongside GFS and ECMWF IFS, using the same coordinates, time filters and JSON or CSV responses. No new request format to learn.

Global coverage, not just the UK

The Met Office Global Deterministic model is a global configuration of the Unified Model, the Met Office's physics-based weather and climate modelling system. Its output covers the whole world on a 2,560 by 1,920 latitude–longitude grid, at approximately 10 km resolution.

For teams already comparing global forecasts, it adds a different forecasting system to the same workflow. You can examine differences in the timing of a temperature change, the passage of a pressure system, or the strength and direction of surface winds. Compare matching initialization times and lead times, and verify against observations: another model is useful evidence, not a guarantee of a better forecast at every location.

What is included first

The initial GribStream dataset is metofficeglobal10km.

Two details matter when comparing these values with other models. The Met Office screen-level fields are at 1.5 metres, not 2 metres. And relative humidity is a fraction: a returned value of 0.75 means 75%. Temperature is in kelvin; subtract 273.15 for Celsius. These field definitions and units follow the Met Office data sheet.

This first collection does not include precipitation, cloud, radiation or pressure-level fields. It also does not include the UKV regional model or the MOGREPS ensembles. The global deterministic forecast provides one model trajectory, not ensemble probabilities.

Four cycles daily, with longer forecasts twice a day

The source publishes 00, 06, 12 and 18 UTC cycles. The 00 and 12 UTC forecasts reach seven days, with hourly steps through +54 hours, three-hour steps from +57 to +144, and six-hour steps from +150 to +168. Forecast reference time is the model's starting time, not the moment it becomes downloadable: the source registry describes typical availability three to six hours later.

The 06 and 18 UTC runs are shorter. Our inspected source objects include the six selected fields through +69 hours, although the published summaries give different short-cycle endpoints. The model page records that distinction; applications should use the records actually available for their selected cycle.

A familiar point-forecast request

This example selects the 6 September 2026 00 UTC cycle at +54 hours for London. It uses the same /runs interface as other GribStream models. Set GRIBSTREAM_TOKEN to your API token before running it. These dates identify a verified historical cycle; choose a more recent cycle for current forecasts, allowing for the source publication delay.

curl --request POST \
  'https://gribstream.com/api/v2/metofficeglobal10km/runs' \
  --header "Authorization: Bearer $GRIBSTREAM_TOKEN" \
  --header 'Content-Type: application/json' \
  --header 'Accept: application/json' \
  --data '{
    "forecastedFrom": "2026-09-06T00:00:00Z",
    "forecastedUntil": "2026-09-06T01:00:00Z",
    "minHorizon": 54,
    "maxHorizon": 54,
    "coordinates": [
      {"lat": 51.5074, "lon": -0.1278, "name": "London"}
    ],
    "variables": [
      {"name": "air_temperature", "level": "1.5 m above ground", "alias": "temperature_k"},
      {"name": "wind_speed", "level": "10 m above ground", "alias": "wind_ms"}
    ]
  }'

Use /runs to compare specific forecast cycles. Use /timeseries when you want to select by valid time instead. The parameter catalog lists the supported selectors, and the API documentation explains the shared query options.

History and attribution

The Met Office retains a rolling two-year source archive for Global and UKV. That is the upstream limit, not a claim that all of that history is already available in GribStream. The model inventory describes the supported fields and their introduction dates. Available parameters and levels depend on the forecast date. See the expanded Met Office family for the broader Global collection and the regional and ensemble models. Individual source files and forecast steps can be absent, and expired upstream data is no longer accessible; this is not a permanent archive.

British Crown copyright 2023–2025, the Met Office. The source data is available under Creative Commons Attribution–ShareAlike 4.0. Reuse should retain appropriate attribution and follow the license's terms for adaptations. GribStream is independent of, and is not endorsed by, the Met Office. The provider describes this open-data feed as unsupported and advises against relying on it for critical business uses.

Which Met Office fields would be most useful in your workflow next? Tell us whether you need more global surface variables, upper-air fields, UKV detail or ensemble guidance.