April 2013: The average temperature for April 2013 was 8.9°C which was equal to April 2012 and is -1.1°C below the 30year average for Bristol.

This April the rainfall total was about 1/2 the average whilst in April 2012 it was 3 times the average.

The -1.8°C on 2nd April was the lowest April temperature since 1979 when -2.3°C was recorded.

The lowest daily maximum temperature of 6.0°C recorded on the 4th was the lowest since April 18th 2001 when 5.5°C was recorded.

The highest max of 16.2°C on the 15th April this year was the lowest since 16.0°C in April 1986.

For the full summary please go here: http://www.afour.demon.co.uk/weather2013apr.htm

The Meteorological site is situated in an urban housing area approximately one mile to the south of the Centre of Bristol. This area is in a district called Totterdown.

Statistical correlations with the Bristol Meteorological Office site, that was less than two miles to the North and was situated on top of a City Centre office block, were generally good with rainfall and barometric data particularly close.

The site of the station is approximately 34 metres above sea level with the manual instruments mounted in a Stevenson screen. The screen is sited centrally in a small concreted garden area. A Snowdon rain gauge is mounted correctly in the ground but does not have the full open space required around it. A  Davis Vantage Pro2 Plus automatic weather station (AWS) was added in May 2005 and this is mounted 4 feet above a concrete shelter. The wind data is gathered automatically from a Davis Vantage Pro2 Plus anemometer which is sited 3.3 metres (10 feet) above the house top.

Manual observations are still taken at approximately 09:00 hours GMT every day for rainfall and cloud cover. Rainfall manually recorded in the Snowdon rain gauge is entered for the previous day. The wind data is constantly logged and automatically reset at 24:00 hours GMT every day (in the summer BST -1 hour. The Davis rainfall tipping bucket was recalibrated in November 2005 and is now consistently under 3% under recording (an improvement from installation in May 2005 when 10% was more typically the norm).

Since the arrival of the Davis Vantage Pro2 Plus equipment in May 2005 temperatures, humidity and barometric pressure are recorded from the new equipment. These figures will be more accurate and will be taken at exactly 09:00 GMT (in the summer BST -1 hour) as the data is now logged to a computer.

By default the Davis equipment records every parameter for the 24 hour period 00:00 to 23:59 BST or GMT. Data analysis will enable manual data extraction of temperatures and rainfall to 09:00 GMT (adjusted in the summer). Due to the 0.2 mm (tipping bucket) measurements of precipitation recorded by the Davis equipment the Snowdon rain gauge will still be used due to its greater accuracy (see above).