Monthly Weather Review - Pitsford Hall

Headline: Becoming mild with a short Indian summer experienced around the 12th, but becoming bitterly cold towards the end with some unusually early snowfall.

The month opened with an area of low pressure positioned to the north-east and a system of fronts tracking eastwards across the southern half of the British Isles. A fresh north-westerly breeze made it feel chilly across the county and there were showers around interspersed with sunnier intervals. During the first few days of October this low moved steadily eastwards towards southern Scandinavia as a ridge of high pressure developed to the west of Ireland. However, far from promising some fine weather this ridge rapidly broke down on the 4th as some active frontal systems worked in off the Atlantic. The 4th started fine across the county, but prolonged and heavy rain arrived during the evening and continued into the 5th. In total 24.5mm was recorded at Pitsford in the 24 hours ending at 0900GMT on the 6th. In addition to the rain, it remained quite windy too across Northamptonshire with gusts reaching 32mph on both the 3rd and 4th. Frontal systems were still producing rain on the 7th, although temperatures had started to recover by this stage as the wind swung round from the south or south-east.

A ridge of high pressure from the Azores started to move towards the British Isles on the 8th. Frontal systems continued to track across the far north, but the result was calmer conditions across the county. Clearing skies overnight led to a fairly chilly start on the 8th, although the rest of the day saw some prolonged sunshine. The high moved steadily towards the continent over the next few days and although the far north came under the renewed influence of frontal systems, it remained dry across the county and daytime temperatures climbed consistently towards a warm 21.0C on the 12th. There was some good sunshine throughout this period, although the early mornings tended to see mist and fog on the 12th.

By the 14th the European high had lost control over the British Isles and frontal systems worked southwards. Rainfall amounts, however, were slight across the county marked by just a few light showers. However, by the 16th the Azores high was extending north-eastwards again towards the UK and the county enjoyed some fine sunny days on the 16th and again on the 17th. The wind veered north-westerly as the high developed and away from the sunshine it started to feel chilly. Clear skies overnight were allowing temperatures to fall quite markedly.

On the 18th the UK stood between a deep low developing over Iceland and high pressure to the south, now moving as it did earlier in the month towards the continent. A second deepening low to the south-west was driven north-eastwards towards Scotland by this high over the next few days. As pressure continued to fall a strong south-westerly picked up across the county gusting to 39mph on the 19th. The wind maintained reasonably mild conditions for mid to late October. The inevitable rain arrived in the county during the afternoon on the 20th, becoming heavy at times.

Over the next few days conditions settled down as the low moved away to the north-east and high pressure remained in charge across the south. However, the effect of the low was still felt in a fairly brisk south-westerly wind and it started to feel noticeably cooler. Another deep low had developed in the vicinity of Iceland on the 23rd and this served to drive a weather fronts south-eastwards. However, as these fronts came up against how pressure over Europe they introduced only light spells of rain across the county.

By the 25th high pressure had become resident across much of the European continent and this served to steer the next low past the north of Scotland. However, its attendant fronts were fairly active and these finally drove rain into the county overnight into the 26th. Winds picked up too gusting to 30mph on the 25th. Most crucially though the arrival of these fronts was to mark a significant transition in the weather for the remainder of the month. A large anticyclone was forming south-west of Iceland and this served to draw cold Arctic air southwards. Whilst the much of the continent continued to enjoy reasonably mild temperatures, a pool of cold air over the British Isles and Scandinavia gave rise to a distinctly wintry feel. Daytime temperatures struggled, reaching only 6.1C on the 29th following a hard air frost overnight (-2.7C). Wintry showers broke out on the 27th and 28th, with snow recorded on the 28th – the earliest it has fallen in the county since 1934.

Several discrete lows tracked close to the county as the month drew to a close introducing mainly light showers. However, with the wind persisting from the north or north-west it remained bitterly cold for the time of year.

Air Temperatures    
The Highest Maximum:    21.0 C on 12th
The Lowest Maximum:    6.1 C on 29th
The Highest Minimum:    10.2 C on 15th
The Lowest Minimum:    -2.7 C on 29th
The Mean Maximum:    13.7 C  
The Mean Minimum:    5.7 C  
The Overall Mean:    9.7 C  
Difference from the Monthly Mean: -0.3 C  
    
Black Bulb    
Maximum (at 0900):    17.5 C on 13th
Mean (at 0900):    11.8 C  
    
Relative Humidity:    
Highest Relative Humidity (at 0900):  100.0 % on 5th
Lowest Relative Humidity (at 0900):  62.5 % on 3rd
Mean Relative Humidity (at 0900):  86.5 %  
    
Dew Point:    
The Highest Dew Point (0900):   14.4 C on 7th
The Lowest Dew Point (at 0900):  -1.9 C on 29th
The Mean Dew Point (at 0900):   7.4 C  
    
Rainfall:    
Total:      49.9 mm  
Difference from the Monthly Mean:  90.6 %  
Duration:     38.3 hrs  
Highest 24 hour fall (0900 to 0900):  15.4 mm on 4th
Rain Days (>/=0.2mm):    12   
Wet Days (>/=1.0mm):    7   
    
Sunshine:    
Total Duration of Bright Sunshine:  110.1 hrs  
Sunniest day:    8.1 hrs on 21st
No. of days without sunshine:   3   
Difference from the Monthly Mean:  126.1 %  
Cloud cover (mean at 0900):   4.6 oktas  (57.5 %)
    
Pressure (reduced to sea level at 0900):    
The Highest Pressure:    1031.6 mb on 9th
The Lowest Pressure:    994.5 mb on 5th
Mean Pressure (recorded at 0900):  1014.5 mb  
    
Winds    
Run of wind (mean over 24 hrs):  134.5 miles  
Mean daily wind speed:    7.3 mph  
Run of wind (cumulative):   4169.5 miles  
Highest Maximum Gust:   39 mph on 19th
No. of gusts of 50mph or more:   0   
Highest wind strength (at 0900):  23.1 mph on 20th
Mean wind strength (at 0900):   9.1 mph  
    
Winds from the Following Directions:    

N 1 NE 2 E 0 SE 4 S 6 SW 6 W 7 NW 4 Calm 1
    
Concrete     
Lowest Concrete Minimum:   -5.3 C on 29th
Mean Concrete Minimum:   3.6 C  
    
Evaporation    
Piche      59.7 ml  
Pan      24.4 mm    

Days with:    
Thunder:     0   
Hail <5mm:     3   
Hail >/=5mm:     0   
Snow or snow & rain:    1   
Snow lying:     0   
Fog:      1   
Air Frost:     1   
Duration of Air Frost:   7 hrs
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.