May 2023:
It was warmer than average month. The mean
temperature of 14.9°C was 1.2°C degrees above the 30 year average
(1991-2020). Rainfall was below average at 58.3% of the same 30 year
average. All of the 36.4 mm of rain that did fall in the month was in the
first 19 days. Almost half of that monthly total fell in one 24 hour period
on 8th May. From the 20th May there were 12 consecutive days of no rain.
Over the same period the predominate daily wind direction was unusually from
a North Easterly direction. With 63.8% of the maximum sunshine recorded for
May 2023 it was the 2nd sunniest since this data started in 2005. The
average over that period for a May is 55.2%. The highest recorded for the
month was in 2020 when 74.2% of the maximum sunshine was reached.
The lowest daily maximum temperature of 16.2°C on the 8th was the highest
recorded for Bristol since this data started in 1960. The maximum daily wind
speed of 7.8 mph on the 29th was the least windy May day since this data
started in 2006. The maximum gust of 28 mph on the 10th was the equal
lowest, with 2012, since this data began in 1995.
Spring 2023 It was
the13th warmest with respect to the average temperatures, with a mean
temperature of 11.1°C. Continuous data for the city started in 1891. The
spring rainfall of 2023 was the 5th wettest out of 142 years of data with
304.5mm. The 30 year average 1991-2020 is 179.5mm so 2023 represents 170% of
the average.
Annual 2022:
In 132 complete years of Bristol's average temperatures, in 2022 it was the
warmest at 12.7°C. The previous warmest was 2014 when the average
temperature reached 12.5°C. 2022 was 1.1°C above the 30 year average
(1991-2020) of 11.6°C. August was the hottest month with an average
temperature of 20.8°C.
The annual rainfall of 798.4 mm for 2022 was 87.4% of the 30 year average
(1991-2020) for the city of 913.8 mm. The wettest month was November with
157.7 mm (157.0% above the 30 year average 1990-2020) of rainfall whilst the
driest was July with only 17.5 mm of rain. There was measurable rainfall
during the year for 4.2% of the time (371 hours). The first 9 months of 2022
produced 407.6 mm or rain whilst the last three months of the year produced
390.8 mm.
2022 was the least windy year with an average wind speed of 4.2 mph since
records began in 2005. The average for the whole period is 5.4 mph. Notable
was the increase of 'calm' days in 2022 when the wind speed is less than 0.5
mph throughout the day. The average (2005-2022) 1.4% calm days but in 2022
this was 7.1%. There were 20 days of air frost, 3 days, 1 with two
occurrences, of thunderstorms and 3 days of small hail recorded. There was 1
day of snowfall which was lying for 1 day at 09:00 GMT. It was very close to
the average for the percentage of maximum sunshine. In 2022 this was 40.7%
when the annual average is 40.2%. The maximum daily temperature of 36.9°C on
the 18th July was the highest recorded for Bristol. The lowest temperature
of 2022 at -5.8°C recorded on 15th & 16th December was the lowest of any
month since February 2012.
To
view a full report of the Bristol Annual Weather 2021 and a discussion of trends
etc click here. This is a Word created .doc document
which is produced annually for a couple of Bristol Naturalist Society
publications. Please acknowledge the source if quoting any of the contents.
Thank you.
The
2022 Annual summary is here:
http://www.bristolweather.org/weather2022annual.htm
For the full monthly summary please go here:
http://www.bristolweather.org/weather2023
May.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).