July 2022:
The two notable items this month making the
news on a larger scale than just local data was the exceptional maximum
temperature on the 18th and the
continuing lack of normal amounts of rainfall.
The maximum temperature of 36.9°C on the 18th July was the highest ever
recorded at any Bristol site from data starting in 1937. The previous record
was 36.0°C recorded in the city on August 9th 2003. For the month overall it
was the equal 7th warmest on record in 132 years of continuous data. The
average temperature for 2022 was 20.0°C. The highest recorded in Bristol was
21.7°C in 1983. The highest daily mean temperature of 27.9°C on the 19th was
the joint highest of any month since this data started in 1993. The highest
minimum temperature on the 19th of 22.2°C was the highest of any month since
the data started in 1960.
The monthly rainfall
of 17.5 mm was only 25.4% of the 30 year average 1991-2020. This as the
driest July since 13.3 mm was recorded in 2016 and the 12th driest July
since records began in 1853 (13 years missing data). There was no measurable
rainfall from the 4th to the 21st July and only 7 hours of rainfall. In the
last 9 months, since November 2021, the rainfall total was 420.7 mm. The 30
year average (1991-2020) is 672.6 mm so the 9 months in question represents
only 63% of the 30 year average.
The average wind speed for the month was 3.2 mph. This is the lowest for any
July since the data started in 2005.The maximum daily pressture of 1033mb on
8th was the 2nd highest for the month since data started in 1995. The daily
minimum pressure of 1009 mb on the 25th was the highest for a July.
Spring 2022 The
spring of 2022 was the joint 4th warmest, with 2003, with respect to average
temperatures with a mean temperature of 11.6°C. Continuous data
for the city started in 1891. The spring rainfall of 2022 was the 24th
driest out of 141 years of data with 131.5mm. The 30 year average 1991-2020
is
179.5mm so 2022 represents only 73% of the average.
Annual 2021:
In 131 complete years of Bristol's average temperatures in 2021 it was the
joint 10th warmest with (with 1999 & 2015) with an average temperature of
11.9°C. The 2nd warmest month, after July, was September.
The annual rainfall of 891.1 mm for 2021 was 97.5% of the 30 year average
(1991-2020) for the city of 913.8 mm. The wettest month was October with
145.6 mm (145.6%) of rainfall whilst the driest was November with only 14.1
mm (14.0%) of rain.
In 2021 the predominate wind direction was from the SW or WSW accounting for
42.7% of all the wind directions. The annual average pressure of 1017 mb
was the equal 3rd highest in 27 years of data at this site. It was the least
windy year since data began in 2005 with regard to the average wind speed.
There were no wind gusts over 50 mph for the 1st time in 4 years. Thunder
was only heard on 1 occasion. In 2021 there were only 4 occasions when
snowfall was observed to fall and only 1 had any snow lying at 09:00 hours.
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
2021 Annual summary is here:
http://www.bristolweather.org/weather2021annual.htm
For the full monthly summary please go here:
http://www.bristolweather.org/weather2022
July.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).