The sun shines in space over data symbols.

Datasets

The HadUK-Grid gridded and regional land surface climate observation datasets are provided under open government licence.

Variables and periods available:

Daily climate variables

Climate Variable id Definition Start Year
Maximum air temperature tasmax Maximum air temperature measured between 0900 UTC on day D and 0900 UTC on day D+1 (oC) 1960
Minimum air temperature tasmin Minimum air temperature measured between 0900 UTC on day D-1 and 0900 UTC on day D (oC) 1960
Precipitation rainfall Total precipitation amount measured between 0900 UTC on day D and 0900 on day D+1 (mm) 1891

Monthly, seasonal and annual climate variables

Climate Variable id Definition Start year
Maximum air temperature tasmax Average of daily maximum air temperature over the calendar month, season or year (oC) 1884
Minimum air temperature tasmin Average of daily minimum air temperature over the calendar month, season or year (oC) 1884
Mean air temperature tas Average of daily mean air temperature over the calendar month, season or year (oC) 1884
Precipitation rainfall Total precipitation amount over the calendar month, season or year (mm) 1836
Sunshine duration sun Duration of bright sunshine during the month, season or year (hours) 1910
Mean wind speed at 10 m sfcWind Average of hourly mean wind speed at a height of 10 m above ground level over the month, season or year (knots) 1969
Mean sea level pressure psl Average of hourly (or 3-hourly) mean sea level pressure over the month, season or year (hPa) 1961
Mean relative humidity hurs Average of hourly (or 3-hourly) relative humidity over the month, season or year (%) 1961
Mean vapour pressure pv Average of hourly (or 3-hourly) vapour pressure over the month, season or year (hPa) 1961
Days of ground frost groundfrost Count of days when the grass minimum temperature is below 0 oC (days) 1961
Days of snow lying snowLying Count of days with greater than 50% of the ground covered by snow at 0900 UTC (days) 1971

Long term average climatologies

Period Description Notes
1961-1990 Standard reference climatology period providing monthly, seasonal and annual averages for 1961 to 1990 Not available for snowLying
1981-2010 Standard reference climatology period providing monthly, seasonal and annual averages for 1981 to 2010  
1991-2020 Standard reference climatology period providing monthly, seasonal and annual averages for 1991 to 2020  
1981-2000 20 year reference climatology period provided for use with UKCP18 products  

Resolutions and domains available

The HadUK-Grid dataset is produced on a 1km x 1km grid resolution on the Ordnance Survey's National Grid

To facilitate comparison of the observational dataset with the UKCP18 climate projections the dataset is also provided at 12km, 25km and 60km resolution. All the gridded datasets use the same grid projection. The re-gridding is conducted through averaging of all 1km grid points that fall within each of the coarser resolution grid cells.

Area averages are also produced based on averaging the 1km grid across a set of geographical regions to provide spatial statistics for country, administrative regions and river basins. The details of these areas can be found in the UKCP18 guidance notes and the associated shapefiles.