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Forecast

Today

Forecast icon

Issued: 03/05/2016 10:03:00

Pollution Band: Low

Details

Wednesday is forecast to be a warm day with plenty of sunshine and an early south-westerly breeze changing to southerly by late morning. The breeze throughout the day is expected to be light, ensuring a relatively clean Atlantic air flow.

In light wind conditions, particulate and nitrogen dioxide levels may enter the 'Moderate' banding during rush hours at busy roadside locations. Overall though, air pollution is expected to remain 'Low' for the following pollutants throughout the forecast period:

Nitrogen Dioxide
Sulphur Dioxide
Ozone
PM10 particulates
PM2.5 particulates








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: 04/05/2016 11:47:00

Start: Thursday 5 May

Finish: end of Thursday 5 May

Pollution Band: Moderate

Details

The fine, settled conditions of the last few days are expected to continue throughout Thursday.

Critically however, a change in wind direction from southerly to south-easterly is forecast for Thursday. Under these conditions, importation of 'stagnant' air which has picked up industrial and agricultural emissions from sources over continental Europe is expected throughout the day. This incoming air will combine with locally-emitted pollutants and is predicted to result in 'Moderate' levels of PM10 and PM2.5 Particulates. With the Particulate pollution being 'driven' by an imported air mass, 'Moderate' levels are likely to occur at background locations as well as close to congested roads.

With temperatures reaching the high teens, long periods of unbroken sunshine and the south-easterly air feed importing photochemical precursors, increased atmospheric photochemistry is expected on Thursday. Although still relatively early in the year, it's possible that these conditions will result in 'Moderate' levels of Ozone at background locations.

As temperatures continue to rise on Friday and into the weekend, 'Moderate' Ozone levels are likely at background locations across Greater London.

Air pollution is expected to remain 'Low' for the following pollutants throughout the forecast period:

Nitrogen Dioxide
Sulphur Dioxide
Ozone









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.