Monthly Weather Review - Pitsford Hall

September began with an anticyclone dominating the picture across the UK. Over the first few days, the centre of this low drifted towards Scandinavia encouraging a run of south-easterly winds. Fine weather was experienced across the county with daytime temperatures climbing to the low 20s, although overnight lows fell quite sharply under clear skies. The 1st, 2nd and 3rd saw reasonable amounts of sunshine, although cloud amounts increased on the 4th helping to lift overnight temperatures.

A deep low moved northwards across Ireland during the 6th and 7th and its attendant frontal system introduced a fair amount of rain across the county. 14.3mm was recorded over 4 hours at Pitsford on the 6th accompanied by quite a fresh breeze. Showers followed this rain across many areas, although at Pitsford it remain dry albeit overcast at times. Storm clouds developing on the 8th never materialised into rain. A succession of frontal systems was ushered in on the 9th with outbreaks of rain (3.8mm at Pitsford) and showers on subsequent days. The situation remained unsettled until the 12th when a transitory ridge ensured a fine day with some prolonged spells of sunshine. However, very quickly on the 13th further frontal systems worked eastwards across the UK, the main area of rain reaching the county late on the 14th. It became quite breezy too with gusts reaching 30mph at Pitsford on the 14th.

The period from the 15th to the 17th saw a notable downturn in temperatures accompanied by a change in wind direction from the north or north-west. From a high of 20C on the 14th, temperatures on the 15th reached just 15.2C and remained in the mid teens on subsequent days. There were some good spells of sunshine. However, clear skies only served to lower overnight temperatures. A milder south-westerly airflow was reinstated on the 18th and this helped to lift temperatures over the next few days. In fact, by the 21st the wind had backed to an even milder southerly direction allowing daytime maxima to creep above 20C.

A depression moved south-eastwards across the UK on the 23rd. Frontal systems associated with this introduced outbreaks of rain across the county. As winds swung round from the north or north-west the following day, temperatures once again fell noticeably. In fact, daytime temperatures at Pitsford only managed 12.4C on the 24th and overnight lows also suffered with a chilly 4.4C overnight into the 25th. It then remained generally unsettled until the month’s close with further outbreaks of rain, notably on the 29th when 7.8mm was recorded at Pitsford.

Air Temperatures    
The Highest Maximum: 22.0 C on 11th
The Lowest Maximum: 12.4 C on 24th
The Highest Minimum: 15.5 C on 11th
The Lowest Minimum: 4.2 C on 20th
The Mean Maximum: 18.1 C  
The Mean Minimum: 9.9 C  
The Overall Mean: 14.0 C  
Difference from the Monthly Mean: + 0.1 C  
    
Solar Radiation    
Maximum (at 0900): 457.0 W/m^2 on 9th
Mean (at 0900): 229.4 W/m^2  
    
Relative Humidity:    
Highest Relative Humidity (at 0900): 100.0 % on 27th & 29th
Lowest Relative Humidity (at 0900): 63.0 % on 6th
Mean Relative Humidity (at 0900): 84.4 %  
    
Dew Point:    
The Highest Dew Point (0900): 15.6 C on 14th
The Lowest Dew Point (at 0900): 4.2 C on 25th
The Mean Dew Point (at 0900): 11.5 C  
    
Rainfall:    
Total: 47.2 mm  
Percentage of the Monthly Mean: 84.3 %  
Duration: 46.5 hrs  
Highest 24 hour fall (0900 to 0900): 14.3 mm on 6th
Rain Days (>/=0.2mm): 12   
Wet Days (>/=1.0mm): 10   
    
Sunshine:    
Total Duration of Bright Sunshine: 113.4 hrs  
Sunniest day: 8.5 hrs on 1st
No. of days without sunshine: 3   
Percentage of the Monthly Mean: 73.1 %  
Cloud cover (mean at 0900): 6.0 oktas 75 %
    
Pressure (reduced to sea level):    
The Highest Pressure (at 0900): 1024.7 mb on 13th
The Lowest Pressure (at 0900): 1000.4 mb on 7th
Mean Pressure (at 0900): 1015.0 mb  
    
Winds    
Run of wind (mean over 24 hrs): 101.9 miles  
Mean daily wind speed: 5.5 mph  
Run of wind (cumulative): 3057.8 miles  
Highest Maximum Gust: 45 mph on 24th
No. of gusts of 50mph or more: 0   
Highest wind strength (at 0900): 25.4 mph on 24th
Mean wind strength (at 0900): 8.4 mph  
    
Winds from the Following Directions:    

N 3 NE 1 E 3 SE 4 S 7 SW 4 W 1 NW 6 Calm 1
    
Concrete     
Lowest Concrete Minimum: 3.3 C on 25th
Mean Concrete Minimum: 9.6 C  
    
Evaporation    
Piche 72.2 ml  
Pan 47.07 mm     

Days with:    
Thunder: 0   
Hail <5mm: 0   
Hail >/=5mm: 0   
Snow or snow & rain: 0   
Snow lying: 0   
Fog: 0   
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.