September 2018:
The average temperature for September of 15.3°C was equal to the 30 year
average for the city, whilst rainfall was around 70% of the average monthly
rainfall.
The average monthly pressure of 1021 mb was the highest for a September
since 1022 mb was recorded in September 2003, and equal with 2007.
The high air pressure of 1039.1 mb recorded on the 24th September was the
highest of any day since 1044.2 mb was recorded on 27th December 2016. It
was also the highest pressure of any September day since this data started
in 1995.
The lowest daily minimum temperature of 4.2°C on the 25th was the lowest for
a September day since 3.7°C was recorded on September 24th 2003.
Annual 2017:
The annual average temperature of 12.1°C in 2017 was 0.8°C above the 30 year
average for Bristol. This makes 2017 the 3rd warmest year (equal with 1989,
1990 and 1997). Continuous records for average temperature having been found
since 1891 in Bristol.
The Total rainfall for 2017 was 751.0 mm. This is 138.9 mm less than the 30
year average for Bristol and the driest year since 2011 when only
723.1 mm was recorded. 2017 was the 39th direst year in Bristol in 165 years
of continuous annual data for the city.
It was the dullest year on record since this data started in 2005 with a
annual average 0f 37.7% of maximum sunshine. The average is 40.0%..
The
2017 Annual summary is here:
http://www.bristolweather.org/weather2017annual.htm
For the full monthly summary please go here:
http://www.bristolweather.org/weather2018sep.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).