Monthly Weather Review - Pitsford Hall

Headline: The dullest August in Northampton since 1986. Frequent showers and longer spells of rain made it also the wettest August since 2004.

August began with a fairly complex area of low pressure covering the UK with its main centre placed over Ireland. A succession of frontal systems brought spells of rain across the county. Daytime temperatures were fairly modest for early August at 22C owing to a fair amount of cloud, although this cloud held overnight lows up at around 13 or 14C. In fact this pattern of temperature fluctuation and its cause was fairly typical of the month as a whole. A weak ridge of high pressure built up over the UK from the south late on the 4th to give some good afternoon sunshine, although it was quickly displaced by active frontal systems tied into a deepening low tracking towards the south-west of Ireland. The 5th turned out to be a fairly wet day with 11.3mm of rain falling over 6 hrs at Pitsford.

Low pressure again would remain fairly stationary across the UK for the next few days, eventually edging further eastwards on the 8th as another ridge of high pressure developed west of Ireland. The day remained dry albeit rather cloudy. However, as before this ridge was short-lived presenting no resistance to the next fairly complex low pressure system as it moved in off the Atlantic late on the 9th. 5.8mm fell as a cold front worked south-eastwards late in the day accompanied by some fairly brisk winds. The county remained caught between fronts on the 10th and so the day was dry with good spells of sunshine. However, another active front introduced some particularly heavy rain overnight on the 11th running into the 12th. 24.7mm was recorded at Pitsford in a little under 5 hours, including some torrential downpours during the morning.

Once more the low which brought the heavy rain on the 12th was slow moving and continued to feed further showers and longer spells of rain across the county over the next few days. There were some good spells of sunshine in between the showers, sufficient in some places to trigger some thunderstorms on the 15th although none were recorded at Pitsford. Temperatures continued to be modest for mid-August with daytime highs failing to reach 20C between the 11th and the 14th, the extra warmth on the 15th fuelling the storms.

The pressure situation on the 15th was fairly slack, some weak occlusions having been caught up in a weak ridge building up from the south. However, low pressure regained control on the 16th merging fairly quickly with a second low moving in off the Atlantic on the 17th. This low remained across the UK until the 20th introducing yet more cloud and rain. The low had begun to fill on the 20th and over the next few days pressure attempted to work in from the west, although the county continued to come under the influence of frontal systems working southwards along the east coast.

Not until the 25th did the situation improve. An area of high pressure which had been resident over mainland Europe extended its influence northwards and started to introduce more settled weather across the south of the UK as far as Northamptonshire, the far north meanwhile still suffering from some fairly active fronts tied into a deep low moving south of Iceland. Although the next few days remained dry across the county, there was little in the way of sunshine. However, as warmer air was drawn in from the near continent daytime temperatures did recover slightly from the 28th reaching a maximum of 24.5C on the 30th which also enjoyed some limited sunshine. Despite the promising end to August, an active low moving up from France ensured a dull and showery day on the 31st with even some extensive fog to start the day.

Air Temperatures    
The Highest Maximum:    24.5 C on 30th
The Lowest Maximum:    17.0 C on 13th
The Highest Minimum:    16.0 C on 30th
The Lowest Minimum:    8.6 C on 23rd
The Mean Maximum:    20.2 C  
The Mean Minimum:    12.8 C  
The Overall Mean:    16.5 C  
Difference from the Monthly Mean:  +0.1 C  
    
Black Bulb    
Maximum (at 0900):    27.8 C on 4th
Mean (at 0900):    19.4 C  
    
Relative Humidity:    
Highest Relative Humidity (at 0900):  98.0 % on 18th
Lowest Relative Humidity (at 0900):  70.3 % on 4th
Mean Relative Humidity (at 0900):  85.6 %  
    
Dew Point:    
The Highest Dew Point (0900):   16.7 C on 6th
The Lowest Dew Point (at 0900):  10.7 C on 13th
The Mean Dew Point (at 0900):   13.4 C  
    
Rainfall:    
Total:      86.0 mm  
Difference from the Monthly Mean:  176.6 %  
Duration:     52.4 hrs  
Highest 24 hour fall (0900 to 0900):  24.7 mm on 11th
Rain Days (>/=0.2mm):    19   
Wet Days (>/=1.0mm):    14   
    
Sunshine:    
Total Duration of Bright Sunshine:  131.6 hrs  
Sunniest day:     10.7 hrs on 15th
No. of days without sunshine:   4   
Difference from the Monthly Mean:  77.5 %  
Cloud cover (mean at 0900):   6.9 oktas (86.3 %)
    
Pressure (reduced to sea level):    
The Highest Pressure:    1021.1 mb on 28th
The Lowest Pressure:    987.0 mb on 12th
Mean Pressure (recorded at 0900):  1009.8 mb  
    
Winds    
Run of wind (mean over 24 hrs):  99.7 miles  
Mean daily wind speed:    5.4 mph  
Run of wind (cumulative):   3090.3 miles  
Highest Maximum Gust:   32 mph on 22nd
No. of gusts of 50mph or more:   0   
Highest wind strength (at 0900):  16.1 mph on 8th
Mean wind strength (at 0900):   7.7 mph  
    
Winds from the Following Directions:    

N 1 NE 0 E 0 SE 3 S 9 SW 13 W 2 NW 2 Calm 1
    
Concrete     
Lowest Concrete Minimum:   6.0 C on 15th
Mean Concrete Minimum:   11.5 C  
    
Evaporation    
Piche      73.3 ml  
Pan      49.61 mm    
  
Days with:    
Thunder:     0   
Hail <5mm:     0   
Hail >/=5mm:     0   
Snow or snow & rain:    0   
Snow lying:     0   
Fog:     1   
Air Frost:     0   
Gales:      0  
All data © Pitsford Hall weather station.

The weather station publishes a full Monthly Weather Report (ISSN 1741-4733) which is distributed to libraries across Northamptonshire. This report comprises a full UK weather diary, reports of extreme weather events across the county, statistics from Pitsford Hall's affiliated stations across the county as well as news from the weather station itself. Individuals may download this report for £2 or take out an annual subscription for the paper-based report for £25. Click here for further details.