St Louis Weather Conditions and Forecast, December 20, 2017

St Louis Weather Conditions and Forecast, December 20, 2017

St Louis Weather Conditions, Forecast & Air Quality Index readings published by STL.News

ST LOUIS, MO/December 20, 2017 (STL.News) St Louis weather conditions & forecast readings from the St. Louis Lambert International Airport at 4:51 a.m at Latitude: 38.75°N, Longitude: 90.37°W – Elevation 604 feet.  Forecast is provided by the National Weather Service (N.W.S.).

Current Weather Conditions


Temperature: 39°F – 4°C
Humidity: 53%
Wind Speed: NE 9 mph
Barometer: 30.06 in (1018.3 MB)
Dew-point: 23°F – -5°C
Visibility: 10 Miles
Wind Chill: 33°F – 1°C
Heat Index: N/A°F – N/A°C

Extended Weather Forecast for the St Louis, Missouri area beginning December 20, 2017

Today: Cloudy gradual clearing – high near 51 with northeast wind 7 to 9 mph.
Tonight: Increasing clouds – low around 35 with southeast wind around 7 mph.
Thursday: Mostly cloudy – high near 54 with south wind 5 to 7 mph.
Thursday Night: 20 percent chance of rain, after midnight, mostly cloudy – low around 42 with south wind around 5 mph turning light/variable.
Friday: 30 percent chance of rain in the pm, cloudy – high near 46 with northwest wind – 6 mph.
Friday Night: Chance of rain followed by a slight chance of snow after 2 am, cloudy – low around 31 with chance of precipitation – 50%.
Saturday: Partly sunny – high near 36.
Saturday Night: 20 percent chance of snow after midnight, mostly cloudy – low around 22.
Sunday: 30 percent chance of snow, mostly cloudy – high near 32.
Sunday Night: Partly cloudy – low around 20.
Christmas Day: Mostly sunny – high near 32.
Monday Night: Partly cloudy – low around 17.
Tuesday: Mostly sunny – high near 30.

Air Quality Index for Saint Louis, Missouri – (A.Q.I.)

Delayed Air Quality Index: 12/20/17 1:00 AM CST

  • Moderate – 69 AQI – Particle Pollution (2.5 microns)
  • Good – 5 AQI – Ozone
  • Good – 17 AQI – Particle Pollution (10 microns)

Agency: St. Louis Metropolitan Area (American Lung Association)

Air Quality Index (A.Q.I.)

Good – Air quality in considered “satisfactory” and air pollution poses little to no threat.

Moderate – Air quality is considered “acceptable.” However, some pollutants there may be a moderate health concern for a very small number of people who are sensitive to air pollution.

USG – while the general public will not likely be affected by this AQI range, people with lung disease, older adults and children are a great risk from exposure to ozone, whereas, persons with heart and lung disease, old adults and children are at greater risk from the presence of particles in the air.

Unhealthy – Everyone may begin to experience health effects members of sensitive groups may experience more serious health effects.

Very Unhealthy – Health Alert: everyone may experience more serious health effects.


Source: Current Weather Conditions and Forecast are obtained from the National Weather Service @ Forecast.Weather.Gov – Air Quality Index (AQI) readings are obtained from AirNow.Gov – (MS)


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