Large Data Set

What is the northernmost UK weather station?

Leuchars

May - October of

1987 and 2015

What is the northernmost English weather station?

Leeming

What is the westernmost UK weather station?

Camborne

Which weather station is closest to London?

Heathrow

Which UK weather station is closest to the Isle of Wight?

Hurn

In alphabetical order, what are the three overseas weather stations?

Beijing, Jacksonville, Perth

In what unit (and tenths) is the daily mean temperature measure in?

Degrees Celcius - average of the hourly temperature during a 24 hour period

Between which times (at GMT) is the daily mean temperature measured?

09:00 to 09:00

What would be seen if no data was available for daily mean air temperature?

n/a

Between which times (at GMT) is the daily total rainfall measured?

09:00 to 09:00

What does a tr / trace value mean for daily total rainfall?

<0.05mm

What unit is daily total rainfall measured in?

Millimetres

What would be seen if no data was available for daily total rainfall?

n/a

What is daily total sunshine measured in?

Nearest tenth of an hour (of bright sunshine)

What would be seen if no data was available for daily total sunshine?

n/a

What is daily maximum relative humidity a measure of?

How close the air is to being saturated with water vapour.

What is a relative humidity of 95% and above associated with?

Mist and fog.

What would be seen if no data was available for daily maximum relative humidity?

n/a

What are wind speeds measured in?

Knots - unit of speed equal to one nautical mile per hour

What is one knot approximately equal to, in mph?

1.15 (mph)

To how many degrees is the daily mean wind direction rounded?

(To the nearest) 10 (degrees)

What is the daily maximum gust direction?

The direction from which the wind was blowing during the maximum gust

What is the daily maximum gust speed?

The highest instantaneous speed which occurred during the 24 hours on the date given

What other type of direction is given for windpseeds?

Cardinal (compass) direction and bearings

What would be seen if no data was available for wind speeds?

n/a

What is the name of the unit in which cloud cover is measured in?

Oktas

How much is an Okta?

One eighth

What is cloud cover?

The fraction of the celestial dome covered by cloud

How would visibility be defined at daytime?

The greatest distance at which an object can be seen and recognised in daylight

How would visibility be defined at nighttime?

The greatest distance at which an object can be seen and recognised if the general illumination were raised to daylight level

In which direction is visibility measured?

Horizontally

What is visibility measured in?

Decametres

What would be seen if no data was available for visibility?

-

From what level is the mean sea level pressure calculated?

Station level

What was previously used as the unit of pressure?

Millibars

Which SI unit is currently used as the unit of pressure?

Hectopascals

What is one hectopascal equal to?

One millibar

Describe how air temperature is measured

By thermometers in a louvered screen 1.25 metres above short grass

What are the exceptions to how air temperature and humidity is measured?

At some Weather Centre's and Climate Data Logger stations from a non-standard roof top exposure

In British Summer Time, when do the 24 hour measuring periods start?

10:00

Daily Total Rainfall also includes

solid precipitation which is melted

What device measures visibility,?

Visiometer

Windspeed is measured from what time, over…?

00:00 GMT, 24 hours

What are the categories for the Beaufort scale corresponding to 0, 1-3, 4 and 5 respectively?

Calm, Light, Moderate, Fresh

Give the range of windspeeds, in knots, for calm, light, moderate and fresh speeds respectively.

<1, 1-10, 11-16, 17-21

What are the only data recorded in overseas stations?

Daily mean: rainfall, temperature, pressure, windspeed

Coastal locations are typically

windier

Northern locations are typically

colder

For 2015 the windiest month on average, for all stations, was

May

In the UK in 2015, the wettest month on average was

August

Worldwide, the wettest city in 2015 was

Jacksonville

In 2015 the wettest UK city was

Camborne

The warmest UK location on average in 2015

Heathrow

In 2015, in order of mean temperature for overseas stations

Jacksonville, Beijing, Perth

Why is Perth pretty cold during the range of months given compared to the rest of the world?

It is in the southern hemisphere whereas the rest are in the northern hemisphere. So the seasons occur at different times.

Why is it important to know where measurements are taken?

For consistency and comparison

What type of data is in the data set, in terms of collection?

Secondary

Why is it important to know about windspeed and maximum wind gusts for Heathrow?

It is an airport, wind greatly affects landing and taking off.

5 UK Weather Stations

✅ Camborne - Coastal

✅ Hurn - Coastal

✅ Heathrow - Inland

✅ Leeming - Inland

✅ Leuchars - Coastal

3 International Weather Stations

✅ Jacksonville - Coastal

✅ Perth - Coastal

✅ Beijing - Inland

11 Variables

Daily Mean Temperature

✅ Daily Total Rainfall

✅ Daily Total Sunshine

✅ Daily Maximum Relative Humidity

✅ Daily Mean Windspeed

✅ Daily Maximum Gust

✅ Daily Mean Wind Direction

✅ Daily Maximum Gust Direction

✅ Cloud cover

✅ Visibility

✅ Pressure

Daily Mean Temperature

✅ degrees Celsius / °C

✅ average of hourly temperature readings during a 24 hour period

Daily Total Rainfall

✅ millimetres / mm

✅ tr/trace < 0.05mm rainfall

✅ tr should be taken as 0 when calculating a mean

Daily Total Sunshine

✅ recorded to nearest 1/10 of an hour

✅ shows the amount of bright sunshine recorded on the day of entry

✅ measured by an instrument that measures the amount of solar radiation exceeding a threshold

Daily Maximum Relative Humidity

✅ % of air saturation with water vapour

✅ a measure of how close the air is to being saturated with water vapour

✅ relative humidities of above 95% are associated with mist and fog

Daily Mean Windspeed

knots (nautical miles per hour) / kn

✅ 1kn = 1.15 mph

✅ averaged over the 24 hours from 0000GMT on the date given

✅ also given on Beaufort Scale

✅ also listed as cardinal directions for UK locations

Daily Maximum Gust

✅ knots (nautical miles per hour) / kn

✅ maximum instantaneous speed

✅ occurs during 24 hours from 0000GMT on the date given

Daily Mean Wind Direction

✅ degrees from true north / °

✅ cardinal direction

✅ ​rounded to the nearest 10 degrees