Pitsford Hall Weather Station

Northampton, UK

Review of the Month - August 2005


Headline: Rather unsettled with frequent showers. The failure of a cold
front to reach the county saw a heatwave in the last few days.


Despite a very unsettled start to the month in many areas the county escaped
any significant rainfall until the 4th. 5.3mm were recorded at Pitsford Hall
over a period of 8.5 hours. Prior to this there were some pleasantly warm
days with decent spells of sunshine. Temperatures on the 2nd climbed to
24.3C with a good 9.6 hours of bright sunshine.


High pressure built over the region from the 7th. Whilst temperatures by day
were again warm overnight temperatures fell quite sharply. Overnight on the
7th was particularly chilly for the time of year with lows of 7.6C (3.6C
over grass). With high pressure came some good spells of sunshine: 12.6
hours on the 8th, 9.4 hours on the 9th. Only a very light shower on the 9th
broke up a protracted spell of dry weather which ran until the 13th.


Unsettled conditions began to prevail across much of the UK from the 10th.
As temperatures rose (rising to 25.5C at Pitsford Hall on the 11th), there
were thundery downpours across many areas although the county escaped the
heaviest of these. 6.9mm was delivered in 3.6 hours at Pitsford on the 13th
which turned out to be a fairly cool and gloomy day for the time of year.


High pressure became re-established after the 13th and this led to a
recovery in temperatures to the mid 20s. There were some occasions of mist,
fog and poor visibility due to haze in the early mornings, but the strong
sunshine soon burnt this away giving some respectable totals: 12.2 hours on
the 17th and 11.8 hours on the 18th.


An active cold front worked through the county on the 18th. A thunderstorm
overnight on the 18th-19th delivered 13.1mm of rain in just under 3 hours at
Pitsford. At one point the intensity of rainfall reached 78.7mm per hour.
The 20th was a reasonably fine day before a further band of heavy rain
delivered 11.3mm in just under 3 hours.


An unseasonably deep area of low pressure tracked to the north of the
British Isles on the 24th. Parts of the north and west were affected by gale
force winds and heavy rain, although the county escaped lightly essentially
with just showers. Even the wind remained calm by comparison to more exposed
regions with a high of just 26mph on the 24th.


As the low moved out of the way temperatures began to recover. A cold front
failed to reach the county on the 29th and this allowed the heat to increase
finally to 31.0C on the very last day on the month. This heat triggered a
spectacular thunderstorm during the evening with 10.5mm of rain recorded in
just 1.5 hours at Pitsford. Some homes in Northampton suffered isolated
flooding.



Climatological Statistics


Air Temperatures
The Highest Maximum: 31.0C on 31st
The Lowest Maximum: 16.9C on 22nd
The Highest Minimum: 14.1C on 3rd & 31st
The Lowest Minimum: 7.6C on 7th
The Mean Maximum: 21.9C
The Mean Minimum: 11.4C
The Overall Mean: 16.7C
Difference from the Monthly Mean: +0.1C

Relative Humidity:
Highest Relative Humidity (at obs): 97.0% on 22nd
Lowest Relative Humidity (at obs): 58.1% on 3rd
Mean Relative Humidity (at obs): 77.6%

Dew Point:
The Highest Dew Point (at obs): 17.7C on 31st
The Lowest Dew Point (at obs): 8.7C on 7th
The Mean Dew Point (at obs): 13.0C

Rainfall:
Total: 54.7mm
Difference from the Monthly Mean: 112.3%
Duration: 24.8hrs
Highest 24 hour fall (obs to obs): 13.1mm on 18th
Rain Days (/=0.2mm): 12
Wet Days (/=1.0mm): 9

Sunshine:
Total Duration of Bright Sunshine: 187.4hrs
Sunniest day: 12.6hrs on 8th
Days without sunshine: 1
Cloud cover (mean at obs): 5.1oktas (63.8%)

Pressure (reduced to sea level):
The Highest Pressu 1025.8mb on 4th & 15th
The Lowest Pressu 1002.4mb on 25th
Mean Pressure (recorded at obs): 1018.1mb

Winds
Run of wind (mean over 24 hrs): 90.2miles
Mean daily wind speed: 4.9mph
Highest mean daily wind speed: 9.2mph on 5th
Run of wind (to date): 2794.9miles
Highest Maximum Gust: 29mph on 3rd
Highest wind strength (at obs): 13.8mph on 20th
Mean wind strength (at obs): 6.2mph

Winds from the Following Directions:

N 2 NE 1 E 0 SE 1 S 4 SW 5 W 2 NW 10 Calm 2

Ground Temperatures:
Lowest Grass Minimum: 3.6C on 7th
Mean Grass Minimum: 7.3C
Lowest Concrete Minimum: 7.6C on 7th
Mean Concrete Minimum: 11.4C
Lowest Bare Earth Minimum: 8.1C on 7th
Mean Bare Earth Minimum: 11.1C

Soil/Earth Temperatures:
Surface mean: 17.0C
5cm mean: 16.0C
10cm mean: 16.4C
20cm mean: 16.9C
30cm mean: 17.4C
40cm mean: 17.2C
50cm mean: 17.5C
100cm mean: 16.4C


Days with:
Thunder: 2
Hail less than 0.5mm: 0
Hail greater than/equal to 0.5mm: 0
Snow or snow & rain: 0
Fog 0
Air Frost: 0
Ground Frost: 0
Gales: 0


Total Evaporation (tank) 83.77mm