Synoptic and climate stations

UK weather stations report a mixture of snapshot hourly observations of the weather known as synoptic observations, and daily summaries of the weather known as climate observations.

For instance, hourly temperature is a synoptic observation, but daily maximum and minimum temperature are climate observations; cloud is synoptic but sunshine is climate. Climate observations are made at 0900UTC, with some stations making further climate observations at 2100UTC.  In summer these correspond to 1000BST and 2200BST respectively.

Observations from around 260 UK automatic (synoptic) stations are collected in real time; climate data from these stations also comes in straight after readings are taken. Climate observations from around 140 co-operating observers at manual climate stations are also received in slower time.

All climate stations record daily maximum and minimum air temperature and rainfall amount, recorded over the period 0900-0900UTC (1000-1000BST in summer).

Many stations observe additional elements. The representativity of urban observations to the surrounding urban area can be difficult to judge, and so their data need to be used with caution. Some observations are made from non-standard stations (e.g. located on roof tops) and these are generally not used for routine climate monitoring.