The UK Argo programme data set comprises measurements of ocean temperature and salinity and provides information of surface and subsurface Lagrangian (measuring movement by tracing the path of a passively drifting object) displacement enabling the derivation of currents. The data set includes a mixture of near-real-time (quality controlled to operational ocean forecasting standards) and delayed mode (quality controlled to climate research standards) data collected by profiling floats. The UK floats from part of a global array throughout the world oceans. Real-time data are available within 24 hours of the float surfacing while delayed mode data become available within 12 months of the profile date. Floats drift at their parking depth (between 1000m and 2025m) for 5 or 10 days depending on float programming. Traditionally floats measured temperature and conductivity at regular intervals during their rise to the surface. In October 2007, the Argo programme achieved its goal to have (and maintain) more than 3000 active floats. As of 2012, some newly deployed floats are being programmed to collect data whilst drifting at their parking depth and during their ascent and additional oceanographic parameters, for example fluorescence, optical backscatter, and dissolved oxygen are being trialled for inclusion in the data set. The data has a variety of uses including assimilation into operational weather forecasts in near-real-time to climate research with the delayed mode data. The data set also includes Argo floats deployed by Mauritius, Saudi Arabia (one float in the Red Sea) Ireland and Portugal, as the British Oceanographic Data Centre manages the data from these floats in addition to those of the UK Argo programme.