This dataset contains a set of reference long term averages for observed climate variables on a 5km resolution grid. Where possible, reference climatologies are available for the periods 1961-1990, 1971-2000 and 1981-2010 for each variable. The availability of the variable for the given reference period was dependant on sufficient data being available for the variable for that period. The data were derived from the Met Office gridded land surface climate observations - monthly variables at 5km resolution (see related dataset). The averages are calculated by averaging the 30 monthly or annual gridded datasets for each variable for each averaging period. The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications.

This dataset contains a set of observed monthly climate variables on a 5km resolution grid. The observations are derived from 16 daily climate variables that have been averaged (e.g. daily maximum temperature) or summed (e.g. monthly total precipitation) over calendar months. The input station data originate from the Met Office Integrated Data Archive System (A version of MIDAS is also available through CEDA, although incremental developments to the database such as quality control and data recovery activities may result in some differences compared to the database at the time of production of the UKCP09 data). The gridding process accounts for effects such as latitude, longitude, altitude, coastal influence, and the effect of urban land through the use of normalisation with respect to monthly 1961 – 1990 climate normals, and in the case of some variables a regression model. For more details about the construction see Perry and Hollis (2005). The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications, and a simple timeseries format for users requiring a limited number of points.

A collection of products from rain radars operated by the Met Office and other European agencies for the UK and Europe. This collection includes rain composite plots and data for the UK and Europe, plus single site radar data including rain rate data, single and dual-polar data products. These were produced by the Met Office's Nimrod system. Nimrod is a fully automated system for weather analysis and nowcasting based around a network of C-band rainfall radars. This dataset has the fine-resolution analyses of rain rate for the UK and Europe. The UK has a network of C-band rainfall radars and data form these are processed by the Met Office NIMROD system. Four or five radar scans at different elevations at each site are processed to give the best possible estimate of rainfall at the ground. The main quality checking method is routine evaluation using rain gauges as ground truth. The BADC holds the analyses of rainfall rate at a time resolution of 5 or 15 minutes. Data are available from late 2002. Images are available for the UK as well as a further image including neighbouring European countries from 1999. Data files are available on a 1 km and 5 km Cartesian grid. Single radar site data are available for 2 and 5 km Cartesian grids for various UK radar sites. The value of radar-based data from the Nimrod system has been highlighted repeatedly. For example, in two severe flooding events during 1998 (at Easter over the Midlands and in late October over Wales), estimates of surface rainfall derived from radar data provided evidence of the extent and severity of the rainfall events. The 2 km data files reach to 100 km from the radar, the 5km files to 250 km. Detailed radar site location are given in the Met Office Weather Radar Factsheet. Time resolution is 5 or 15 minutes depending on the product. Various scripts have been made available under the software directory to aid use of these data, including within GIS applications.

This dataset contains a set of observed climate indices on a 5km resolution grid. The data are derived from daily temperature and precipitation grids (see related dataset) to provide annual indicies: 9 temperature based indices (for example summer heatwave duration); and 12 precipitation indices (for example maximum 1 day precipitation amount). The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications, and a simple timeseries format for users requiring a limited number of points.

This dataset contains a set of reference long term averages for observed climate variables on an approximately 25km resolution grid. This matches the resolution of the HadRM3 regional climate model and the UKCP09 climate projections. These data represent the baseline reference climate averages for the period 1961 – 1990. The data were derived from the Met Office gridded land surface climate observations – long term averages at 5km resolution (see related dataset). Each 25 x 25km grid box value is an average of the 5 x 5 km grid cell values that fall within it. Averages have been calculated for each month, season and the year as a whole (17 data sets). For the days of frost and days of rain variables the seasonal and annual averages are the total of the individual monthly averages. For the remaining variables the seasonal and annual averages are the mean of the monthly averages (allowing for differences in month length). To facilitate combining the baseline data with the UKCP09 climate projections, the 25 km baseline averages for rainfall have been expressed in units of millimetres per day (rather than total millimetres, as for the 5 km data sets). The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications, and a simple timeseries format for users requiring a limited number of points.

PILOT reports describe measurements reported up to four times daily by radiosondes at worldwide fixed land stations. The dataset contains measurements of wind speed and direction. The data are measured from the surface to approximately 20-30 km and measurements are usually taken every 2 seconds. These data are provided as-is from the Met Office and so will need the message components bringing together for each ascent The PILOT data contain the following observations: Wind speed at standard pressure levels Vertical wind shear Maximum wind level The data comprise vertical profiles of temperature, dew-point temperature, wind speed and wind direction at standard and significant pressure levels. The standard pressure levels are 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 20 and 10 hPa. Significant pressure levels are calculated according to the Met Office criteria and constitute levels at which significant events occur in the profile, e.g temperature inversions. The data are measured from the surface to approximately 20-30 km. Generally there are up to 4 ascents per day from each station, though some sites may only have 1 or 2 ascents. Ascent times are typically around 00, 06, 12 and 18 UT. A maximum wind level is defined as a level at which the wind speed is greater than that observed immediately above and below that level..

This dataset contains a set of daily observations of temperature (daily maximum, daily minimum and daily mean temperature) and rainfall (24 hour accumulation) interpolated to a uniform 5km grid resolution covering the period 1960 to 2014. The input station data originate from the Met Office Integrated Data Archive System - MIDAS - a database at the Met Office of observation station data stretching back to the 18th century. (A version of MIDAS is also available through CEDA, although incremental developments to the database such as quality control and data recovery activities may result in some differences compared to the database at the time of production of the UKCP09 data - see linked datasets for access to these equivalent datasets held by CEDA). The input station data used provide observations relating to periods 0900 to 0900 UTC, so the gridded output stored against day "dd" are as follows: • Maximum temperature between 0900 on day dd and 0900 on day dd+1 (normally expect to occur during the afternoon of day dd) • Minimum temperature between 0900 on day dd-1 and 0900 on day dd (normally expect to occur just before dawn on day dd) • Mean temperature that is the average of the maximum and minimum temperature • Rainfall (or rainfall equivalent in cases of frozen precipitation) amount between 0900 day dd and 0900 day dd+1 The gridding process accounts for effects such as latitude, longitude, altitude, coastal influence, and the effect of urban land through the use of normalisation with respect to monthly 1961 – 1990 climate normals, and in the case of temperature, a regression model. The data are provide in CF-1.5 compliant NetCDF format. The data are additionally provided in ESRI-ascii format, suitable for ingestion in GIS applications, and a simple timeseries format for users requiring a limited number of points.

Cloud base and backscatter data from the Met Office's Vaisala Ct25k ceilometer located at Wittering, Sussex. The Met Office's laser cloud base recorders network (LCBRs), or ceilometers, returns a range of products for use in forecasting and hazard detection. The backscatter profiles can allow detection of aerosol species such as volcanic ash where suitable instrumentation is deployed.

The Icelandic Volcano, Eyjafjallajokull, started erupting on 14th April 2010. The volcanic ash cloud produced covered much of Northern Europe for several weeks causing extensive disruption to air travel. The UK and European atmospheric communities had many instruments - both airborne and ground-based, remote sensing and in-situ - taking measurements of the ash cloud throughout this period. This dataset contains measurements from Met Office's Laser Cloud Base Recorder (LCBR) network.

The UK daily temperature data contain maximum and minimum temperatures (air, grass and concrete slab) measured over a period of up to 24 hours. The measurements were recorded by observation stations operated by the Met Office across the UK and transmitted within NCM, DLY3208 or AWSDLY messages. The data span from 1853 to 2020. For details on measurement techniques, including calibration information and changes in measurements, see section 5.2 of the MIDAS User Guide linked to from this record. Soil temperature data may be found in the UK soil temperature datasets linked from this record. This version supersedes the previous version of this dataset and a change log is available in the archive, and in the linked documentation for this record, detailing the differences between this version and the previous version. The change logs detail new, replaced and removed data. Of particular note, however, is that as well as including data for 2020, historical data recovery has added further data for Eskdalemuir (1915-1948) and Eastbourne (1887-1910). This dataset is part of the Midas-open dataset collection made available by the Met Office under the UK Open Government Licence, containing only UK mainland land surface observations owned or operated by the Met Office. It is a subset of the fuller, restricted Met Office Integrated Data Archive System (MIDAS) Land and Marine Surface Stations dataset, also available through the Centre for Environmental Data Analysis - see the related dataset section on this record. Currently this represents approximately 95% of available daily temperature observations within the full MIDAS collection.