The UK-AIR website uses cookies to make the site simpler. Find out more about cookies

Low Ozone Events

A low ozone event is defined as a departure of more than two standard deviations below the long-term monthly mean value for the site and is based on provisional data which may be subject to change.

If a low ozone event is detected from the UK monitoring data Defra are informed in near real time and liaise with PHE to issue appropriate public health warnings.

The table below shows days that meet the Low Ozone Event criteria since October 2009.

Lerwick – Date of departure Reading - Date of departure
10-Sep-14 01-Feb-16
16-Oct-13 31-Jan-16
15-Oct-13 04-Apr-15
23-Apr-13 16-Mar-14
27-Mar-12 06-Mar-14
26-Mar-12 21-Sep-13
15-Feb-12 25-Apr-13
31-Jan-12 24-Apr-13
09-Apr-11 23-Apr-13
30-Mar-11 27-Jun-12
29-Mar-11 28-Mar-12
28-Mar-11 24-Feb-12
27-Mar-11 23-Feb-12
16-Feb-12
18-Jan-12
  14-Jan-12
  27-Dec-11
  26-Dec-11
  25-Dec-11
  23-Dec-11
  08-Oct-11
  27-Jun-11
  09-Apr-11
  06-Apr-11
  31-Mar-11

Between July 2000 and February 2013, the following low ozone events were analysed in some detail:

Page last modified: 12 February 2016