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Forecast

Today

Forecast icon

Issued: 24/11/2014 12:41:00

Pollution Band: Low

Details

A still, misty and chilly start to the day is expected and this will inhibit the dispersal of pollutants. 'Moderate' nitrogen dioxide may therefore occur during the morning rush period at busy roadside locations, particularly in central London.

Conditions are expected to improve throughout the day as increasing wind speed and rain by evening promote the dispersion of locally-emitted pollutants. However, back trajectory analysis also indicates that an air mass which has passed over Belgium and Holland will affect Greater London by early evening. This imported air may result in elevated PM10 and PM2.5 particulate concentrations for the remainder of Tuesday although levels are expected to remain in the 'Low' banding.

Air pollution will remain 'Low' throughout the forecast period for the following pollutants:

PM10 Particulates
PM2.5 Particulates
Nitrogen Dioxide
Ozone
Sulphur dioxide





This forecast is intended to provide information on expected pollution levels in areas of significant public exposure. It may not apply in very specific locations close to unusually strong or short-lived local sources of pollution.

Outlook

Forecast icon

Issued: 25/11/2014 13:03:00

Start: Wednesday 26 November

Finish: end of Wednesday 26 November

Pollution Band: Low

Details

Light winds from the east on Wednesday bring with them the chance of imported pollution from the continent. Low wind speeds will also mean poor dispersion of local emissions. Conditions overnight are however expected to be warmer than the last few nights, and periods of rain will also help remove pollutants from the air.

'Moderate' levels of particulate and nitrogen dioxide may occur at busy roadside locations but generally across London air pollution will remain 'Low' throughout the forecast period for the following pollutants:

Nitrogen Dioxide
Ozone
PM10 Particulates
PM2.5 Particulates
Sulphur dioxide





This forecast is intended to provide information on expected pollution levels in areas of significant public exposure. It may not apply in very specific locations close to unusually strong or short-lived local sources of pollution.


How to use the Daily Air Quality Index *

  • Step 1: Determine whether you (or your children) are likely to be at-risk from air pollution. Your doctor may also be able to give you advice.
  • Step 2: If you may be at-risk, and are planning strenuous activity outdoors, check the air pollution forecast.
  • Step 3: Use the health messages corresponding to the highest forecast level of pollution as a guide.
Air Pollution Banding Value Accompanying health messages for at-risk groups and
the general population
At-risk individuals ** General population
Low 1-3 Enjoy your usual outdoor activities.

Enjoy your usual outdoor activities.

Moderate 4-6 Adults and children with lung problems, and adults with heart problems, who experience symptoms, should consider reducing strenuous physical activity, particularly outdoors. Enjoy your usual outdoor activities.
High 7-9 Adults and children with lung problems, and adults with heart problems, should reduce strenuous physical exertion, particularly outdoors, and particularly if they experience symptoms. People with asthma may find they need to use their reliever inhaler more often. Older people should also reduce physical exertion. Anyone experiencing discomfort such as sore eyes, cough or sore throat should consider reducing activity, particularly outdoors.
Very High 10 Adults and children with lung problems, adults with heart problems, and older people, should avoid strenuous physical activity. People with asthma may find they need to use their reliever inhaler more often. Reduce physical exertion, particularly outdoors, especially if you experience symptoms such as cough or sore throat.

* Daily Air Quality Index information sourced from UK-AIR (Air Information Resource) website.

* Adults and children with heart or lung problems are at greater risk of symptoms. Follow your doctor's usual advice about exercising and managing your condition. It is possible that very sensitive individuals may experience health effects even on Low air pollution days.