Monthly Weather Review - Pitsford Hall

Headline: Very dry and sunny. Some very warm days followed by chilly nights.

April began very unsettled and cold. A complex area of low pressure drifted across the UK during the first few days bringing outbreaks of rain across the county. Some particularly heavy spells of rain were reported from elsewhere in the UK, Dorset in particular, although Northamptonshire escaped with just a few millimetres on the 1st and 2nd. Daytime temperatures remained in single figures initially and although these rose steadily from the 2nd, night-time temperatures remained quite chilly. The first week was also quite windy with gusts reaching or exceeding 30mph on several days.

The second week, however, saw the start of a protracted spell of fine and settled weather. High pressure dominated the picture from the 8th right up until the 24th. Whilst the exact focus of this anticyclone would move steadily from England to Scotland and then out across the mid Atlantic later in the period, the dry conditions would persist maintained more by a ridge of high pressure in the third week. The anticyclonic conditions encouraged a fair amount of sunshine and most days recorded respectable totals. Notably sunny spells, however, included the 8th (10.4 hrs), 17th (12.2hrs) and the period from the 20th to the 23rd which saw between 10 and 12 hrs daily. The strengthening sunshine at this time of year had an impact on temperatures during the day with several days recording a maximum in excess of 16C, and up to 19.0C on the 24th (the warmest day of the month). However, with relatively clear skies temperatures fell sharply at night and, whilst the county escaped without an air frost, lows fell to just 1 or 2C several times and as low as 0.6C on the 22nd.

The long spell of dry weather was brought to an end on the 24th as a cold front tracked eastward across the region. However, a mere 0.4mm fell at Pitsford and the front was quickly followed by another ridge of high pressure which maintained settled weather for the next few days. The cold front made little impact on temperatures either as a steady rise beginning on the 22nd continued with daytime maxima falling between 18.0C and 19.0C between the 24th and 28th. Much of this increase resulted from a change in wind direction from the south and night-time minima not falling quite so low as they did earlier.

As the month came to a close further fronts crossed the UK and these introduced more significant falls of rain across Northamptonshire. Both the 29th and 30th were ‘wet days’ with temperatures slightly down on what they had been previously.

Overall, April was significantly drier than normal across Northamptonshire with a distinct lack of ‘April showers’. In fact, although not as dry as April 2007 which saw only 1.6mm fall, it was nonetheless the second driest since 1984 (10.4mm) and the third driest since 1974 (7.4mm). Sunshine levels were up and whilst this brought some unseasonal warmth at times, some nights were decidedly chilly.

Air Temperatures    
The Highest Maximum: 19.0 C on 24th & 28th
The Lowest Maximum: 7.6 C on 1st
The Highest Minimum: 10.5 C on 29th
The Lowest Minimum: 0.6 C on 22nd
The Mean Maximum: 14.5 C  
The Mean Minimum: 4.6 C  
The Overall Mean: 9.6 C  
Difference from the Monthly Mean: 1.4 C  
    
Solar Radiation    
Maximum (at 0900): 604.0 W/m^2 on 16th
Mean (at 0900): 328.2 W/m^2  
    
Relative Humidity:    
Highest Relative Humidity (at 0900): 90.1 % on 7th
Lowest Relative Humidity (at 0900): 45.7 % on 23rd
Mean Relative Humidity (at 0900): 73.3 %  
    
Dew Point:    
The Highest Dew Point (0900): 10.6 C on 29th
The Lowest Dew Point (at 0900): -0.1 C on 1st
The Mean Dew Point (at 0900): 5.1 C  
    
Rainfall:    
Total: 12.4 mm  
Percentage of the Monthly Mean: 27.6 %  
Duration: 11.9 hrs  
Highest 24 hour fall (0900 to 0900): 3.8 mm on 1st
Rain Days (>/=0.2mm): 6   
Wet Days (>/=1.0mm): 5   
    
Sunshine:    
Total Duration of Bright Sunshine: 171.0 hrs  
Sunniest day: 12.3 hrs on 23rd
No. of days without sunshine: 1   
Percentage of the Monthly Mean: 112.2 %  
Cloud cover (mean at 0900): 4.5 oktas 56.3 %
    
Pressure (reduced to sea level):    
The Highest Pressure (at 0900): 1035.5 mb on 10th
The Lowest Pressure (at 0900): 1000.8 mb on 3rd
Mean Pressure (at 0900): 1019.9 mb  
    
Winds    
Run of wind (mean over 24 hrs): 128.8 miles  
Mean daily wind speed: 7.0 mph  
Run of wind (cumulative): 3865.0 miles  
Highest Maximum Gust: 33 mph on 5th
No. of gusts of 50mph or more: 0   
Highest wind strength (at 0900): 20.8 mph on 6th
Mean wind strength (at 0900): 9.2 mph  
    
Winds from the Following Directions:    

N 3 NE 3 E 1 SE 4 S 7 SW 1 W 3 NW 8 Calm 0
    
Concrete     
Lowest Concrete Minimum: -0.4 C on 1st
Mean Concrete Minimum: 4.4 C  
    
Evaporation    
Piche 95.3 ml 
Pan 72.68 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.