State of the UK Climate 2023

This report provides a summary of the UK's weather and climate through the calendar year 2023, alongside the historical context for a number of essential climate variables. This is the tenth in a series of annual ‘State of the UK Climate’ publications, published in the International Journal of Climatology (IJC) since 2017, and an update to the 2022 report (Kendon et al., 2023). It provides an accessible, authoritative and up-to-date assessment of UK climate trends, variations and extremes based on the most up to date observational datasets of climate quality. The majority of this report is based on observations of temperature, precipitation, sunshine and wind speed from the UK land weather station network as managed by the Met Office and a number of key partners and co-operating volunteers. The observations are carefully managed so that they conform to current best-practice observational standards as defined by the World Meteorological Organization (WMO). The observations also passthrough a range of quality assurance procedures at the Met Office before application for climate monitoring. Timeseries of near-coast sea-surface temperature and sea-level are also presented, and in addition there is a short section on phenology that provides dates of ‘first leaf’ and ‘bare tree’ indicators for four common shrub or tree species plus several other indicators. The reliance of this report on these observations highlights the ongoing need to maintain the observation networks, in particular the UK land weather station network, into the future. This is vital if the UK's climate monitoring capability is to be continued.