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| July 2001 monthly assessment issued
1/8/2001 |
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Monthly summaries available for: England
and Wales | Scotland | Northern
Ireland
Homogenous time series based upon selected station data:
CET | England and Wales
rainfall
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| A near normal month statistically. A
hot thundery first week was followed by cool wet unsettled
conditions during the middle fortnight, with some heavy
thundery downpours later. The last week saw dry, sunny, hot
weather almost everywhere for most of the time. |
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Diary of highlights
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1st - 7th It was very warm or hot in many
places during this period with Heathrow reaching 30.5 °C
on the 5th. Thunderstorms early on 3rd over Wales spread
to other parts of England and Wales over succeeding
days, with some heavy downpours in places. Cardiff
received 67 mm in 12 hours ending 09 GMT on the 4th.
High pressure gave way to low pressure in the south-west
approaches, which then slowly transferred to the
southern part of the North sea by the 7th.
8th -
16th A cool unsettled spell ensued as low pressure
over the North sea moved away and another depression off
western Scotland on the 10th moved to the North sea by
the 11th, before migrating to Scandinavia. The 9th and
10th were quite wet as associated fronts crossed England
and Wales. There were frequent showers some heavy with
thunder, but these became more scattered towards the end
of the period. Mumbles (south Wales) reported a gust of
52 knots on the 11th. A shallow low over the south-east
on the 14th was followed by a weak ridge on the 15th and
16th, with zero Celsius being recorded at Sennybridge
(Powys) overnight.
17th - 20th A wet spell
especially the 17th/18th with heavy thundery rain in
many places as a low moved from the south-west
approaches to the North sea. As fronts stalled over East
Anglia and the Midlands, some high totals were recorded.
At Keyworth (Notts) 96 mm fell in 15 hours ending 09 GMT
on the 18th causing considerable local flooding.
Weybourne (Norfolk) received 69 mm the same day, 41 mm
falling in 3 hours that morning.
21st - 24th
After a cool start it became warm with good sunny
periods in most places, although noth-west areas had
more cloud and scattered light showers from time to
time.
25th - 31st Hot sunny weather prevailed
for much of the time as a weak ridge of high pressure
covered the region. Any local mist or fog patches soon
cleared away after sunrise. It was very hot at times in
the south and on the 28th and 29th temperatures hovered
around 32 °C in the London area. From the 29th onwards
northern and western areas were affected by occasional
outbreaks of light rain or drizzle in association with a
weak cold front edging
southwards.
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| Statistical details (using best available
data/estimates): updated 2003 |
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England & Wales Mean Temperature Series (series
began in 1961).
The final value for the month was 16.5 °C, which
is 1.1 °C above the 1961-1990 average, which is
in the above average category.
England & Wales Rainfall Series (series began
in 1961).
The final total for the month was 74.0 mm, which is
119 % of the 1961-1990 average, which is in the close
to average category.
England & Wales Sunshine Series (series began
in 1961).
The final total for the month was 190.0 hours, which is
104 % of the 1961-1990 average, which is in the close
to average category.
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| Scotland |
| Unsettled and dull. |
| Diary of Highlights |
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July was a very dull month across Scotland, a result
of a combination of factors. These included a disturbed
and cyclonic spell, a period of relatively high pressure
with slow moving fronts, and stagnant weather situations
with lots of low cloud.
July started with a warm and humid southwesterly airmass
covering Scotland, giving drizzle in the northwest and bright
conditions in the east. On the 2nd, the temperature at Aberdeen
rose from 16 °C to 27 °C.
On the 3rd winds fell light and
thunderstorms broke out in the southwest, with 30 mm
recorded at Saughall in Ayrshire. The generally cloudy
but warm weather continued on the 4th.
During the
5th and 6th the weather became more settled and the low
cloud broke up inland to give some warm sunshine.
Low pressure moving north up the North Sea brought a
bleak couple of days on the 7th and 8th, with overcast
weather accompanied by outbreaks of rain. Saughall
recorded 45 mm on the 7th.
After a brief respite on the 9th, a spell of cool and overcast
weather with outbreaks of rain began on the 10th as a depression
crossed Scotland and moved into the Norwegian Sea. Skye
experienced 37 mm of rain on the 10th and outbreaks
of light rain continued in the south until the 14th.
A
ridge of high pressure gave sunny periods for a couple
of days on the 15th and 16th. Mainly dry conditions
prevailed from the 17th to the 20th as a low pressure
centre moved across the south of England, causing winds
in Scotland to blow from the east for a while.
Low
pressure to the northwest of Scotland turned winds into
the southwest between the 21st and 24th, and there was
rain or showers in places. However, the 24th was a fine
day.
High pressure in the North Sea prevailed from
the 25th to 28th, but areas of cloud and light rain
waffled across the country.
A westerly airstream
brought sunshine to many parts on the 29th, but a wave
depression brought further rain to central and southern
districts on the 30th. A following ridge of high
pressure gave a sunny last day of the month to the
south.
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Statistical details (using
best available data/estimates): updated 2003
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Scotland Mean Temperature Series (series
began in 1961).
The final value for the month was 13.1 °C, which
is 0.5 °C above the 1961-1990 average, which is
in the close to average category.
Scotland Rainfall Series (series began in 1961).
The final total for the month was 99.6 mm, which is
104 % of the 1961-1990 average, which is in the close
to average category.
Scotland Sunshine Series (series began in 1961).
The final total for the month was 107.5 hours, which is
76 % of the 1961-1990 average, which is in the well
below average category. Dullest since 1980, when 103.3
hours was recorded.
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| Northern
Ireland |
| This was a fairly average July month with rainfall,
sunshine and temperature values being very close to normal.
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Diary of Highlights
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1st to 8th Warm and dry at first turning dull
and cooler by 6th.
9th to 11th Unsettled with
conditions particularly wet on the 9th and 10th.
12th to 19th Cooler, bright and showery but
largely dry for the period 15th to 19th. The 18th was a
particularly sunny day.
20th to 24th
Unsettled with wettest conditions on the 21st.
25th to 31st Warm, bright and largely dry
with only occasional showers. More unsettled on the
30th.
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Statistical details (using
best available data/estimates): updated 2003
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Northern Ireland Mean Temperature Series (series
began in 1961).
The final value for the month was 14.3 °C, which
is 0.3 °C above the 1961-1990 average, which is
in the close to average category.
Northern Ireland Rainfall Series (series began in
1961).
The final total for the month was 62.8 mm, which is
88 % of the 1961-1990 average, which is in the close
to average category.
Northern Ireland Sunshine Series (series began in
1961).
The final total for the month was 132.0 hours, which is
94 % of the 1961-1990 average, which is in the close
to average category.
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Homogeneous series based upon selected station data: updated
2003 |
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Central England Temperature (series begins in 1659).
The mean value for the month was 17.2 °C which is 1.1 °C
above the 1961-90 normal of 16.1 °C and is in the above
average category.
Others:- 2000/15.5, 1999/17.7 °C.
England and Wales Rainfall (series begins in 1766).
The total for the month was 73.2 mm, which is 118 %
of the 1961-90 average and is in the close to average category.
Others: - 2000/63.8, 1999/26.3, 1998/54.4, 1997/53.5, 1993/88.7 mm.
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| Note: Diary values are provisional based
on data available at the time. |
