Weather Statistics for January 2006

Headline: The warmest July in Northampton for 20 years with the 19th being the warmest July day on record. Several intense thunderstorms resulted in above average rainfall.

The month began with much of the UK under the influence of a ridge of high pressure extending from Scandinavia. A weak weather front across the region produced a small amount of rain on the 1st, but otherwise the first few days were dry with some good amounts of sunshine and light winds. It was also exceptionally warm with a high of 31.6C on the 2nd. The continued heat eventually fuelled a spectacular thunderstorm on the afternoon of the 4th which saw 15.5mm falling in less than an hour at Pitsford. Localised flash flooding was reported as well as damaging hail on the A43.

Further thundery showers worked northwards across the county early on the 5th. 6.1mm was delivered in the space of 10 minutes at 08:20 GMT at Pitsford. There were extensive reports of flooding in the St James, Abington Street and Bedford Road areas of Northampton as gutters and drains failed to cope with the intensity of rainfall. 4500 people in Crick, West Haddon and Long Buckby were left without electricity for several hours. Corridors around the stroke unit at Northampton General Hospital's Billing Road entrance were flooded by the downpours. In total 15.5mm of rain fell in the 24 hrs from 0900GMT. The showers brought an end to the heatwave which had begun with rising temperatures at the end of June. By the 7th temperatures were barely reaching the 20 or 21C and daily sunshine amounts were modest for the time of year. Cyclonic conditions prevailed until at least the 10th with spells of rain and/or scattered showers. Eventually, a ridge of high pressure built in across the southern half of the British Isles on the 11th.

The 11th was a fine and dry day across the county with a fair amount of sunshine (11.9hrs). Temperatures had recovered and highs over the next few days would remain stable round about the mid 20s before taking off on the 16th. By the 14th high pressure had become firmly established across the whole of the British Isles, but over the next few days as it moved eastwards across the North Sea towards Scandinavia it began to draw in some very warm air towards the UK. A notable heatwave developed across the county with temperatures exceeding 30C everyday between the 17th and the 21st. On the 19th several stretches of tarmac on the county's roads began to melt forcing gritters to take to main routes with granite dust. Liquefied tarmac was reported between Old and Walgrave, Kelmarsh and Sibbertoft. Speed restrictions were introduced on the railways between Northampton and Birmingham/London amidst fears that tracks could buckle in the heat. The online automatic weather station at Pitsford registers a high of 37.3C at 14:30 GMT triggering frenzied media interest. However, not being a recognised Met Office station the temperature fails to clinch the record for the hottest July day on record in the UK. The temperature measured by Pitsford’s climatological station was 35.5C, yet this still registered as the hottest July day in record in Northampton.

Thunderstorms, triggered by the heat, eventually reached the county on the 22nd. In a spectacular lightning display, 20.5mm was delivered in just 1.6 hrs at Pitsford. Two houses in Lumbertubs, Northampton were flooded by two feet of water and parts of Wellingborough Road resembled a river. Northamptonshire's Fire and Rescue received more than 30 calls during the peak of the storm. The storm left a cooler day on the 23rd, although by the following day temperatures had recovered once more with a high of 31.7C recorded on the 25th. High pressure remained centred over the North Sea keeping weather systems at bay further west. Further thunderstorms rumbled through the county overnight on the 26th/27th, although very little rainfall was recorded at Pitsford. However, power surges left over 1000 homes without electricity across Northampton.

Low pressure, which had been developing south-west of Iceland since the 26th, was eventually to push frontal systems across the British Isles from the 29th onwards bringing the heatwave to an end. Temperatures began to fall back closer to the norm, yet highs were still a degree or so above the seasonal average. A band of fairly heavy and persistent rain on the 31st delivered 15.8mm of rain.


Air Temperatures    
The Highest Maximum:  35.5C on 19th
The Lowest Maximum:  20.1C on 7th
The Highest Minimum:  19.8C on 20th
The Lowest Minimum:  9.6C on 14th & 15th
The Mean Maximum:  26.8C  
The Mean Minimum:   14.4C  
The Overall Mean:   20.6C  
Difference from the Monthly Mean: +3.3C  
    
Relative Humidity:    
Highest Relative Humidity (at obs): 96.2% on 6th
Lowest Relative Humidity (at obs): 30.7% on 19th
Mean Relative Humidity (at obs): 68.1%  
    
Dew Point:    
The Highest Dew Point (at obs): 20.1C on 27th
The Lowest Dew Point (at obs): 9.8C on 8th
The Mean Dew Point (at obs):  15.1C  
    
Rainfall:    
Total:    73.7mm  
Difference from the Monthly Mean: 153.9%  
Duration:    16.4hrs  
Highest 24 hour fall (obs to obs): 20.6mm on 22nd
Rain Days (>/=0.2mm):  12   
Wet Days (>/=1.0mm):  7   
    
Sunshine:    
Total Duration of Bright Sunshine: 278.0hrs  
Sunniest day:   15.5hrs on 18th
Days without sunshine:  0
Cloud cover (mean at obs):  3.8oktas (45.5%) 
    
Pressure (reduced to sea level):    
The Highest Pressure:  1031.9mb on 14th
The Lowest Pressure:  1007.0mb on 9th
Mean Pressure (recorded at obs): 1018.2mb  
    
Winds    
Run of wind (mean over 24 hrs): 82.0miles  
Mean daily wind speed:  4.4mph
Highest mean daily wind speed: 9.1mph on 14th  
Run of wind:   2541.2miles  
Highest Maximum Gust:  37mph on 22nd
Highest wind strength (at obs): 11.5mph on 15th
Mean wind strength (at obs):  4.4mph  
    
Winds from the Following Directions:    

N 4 NE 5 E 3 SE 1 S 4 SW 3 W 3 NW 4 Calm 4   
    
Ground Temperatures:     
Lowest Grass Minimum:  6.1C on 15th
Mean Grass Minimum:  11.3C  
Lowest Concrete Minimum:  8.9C on 19th
Mean Concrete Minimum:  13.3C  
Lowest Bare Earth Minimum:  9.0C on 22nd
Mean Bare Earth Minimum:  14.0C  
    
Soil/Earth Temperatures:     
Surface mean:   22.5C  
5cm mean:   21.7C  
10cm mean:   22.2C  
20cm mean:   21.6C  
30cm mean:   20.7C  
40cm mean:   20.7C  
50cm mean:   20.6C  
100cm mean:   18.0C  
    
    
Days with:    
Thunder:    6   
Hail less than 0.5mm:  0   
Hail greater than/equal to 0.5mm: 0   
Snow or snow & rain:  0   
Fog    2
Ground frost:   0
Air frost:    0
Gales:    0   
      
Total Evaporation (tank)  130.22mm

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 subscribe to this report at a rate of £15 per year. Please contact the station for further information.