Monthly Weather Review - Pitsford Hall

Headline: Dry, sunny and very warm. The 23rd was the warmest April day on the local record.

The month began with warm but changeable southwesterly winds. Amounts of rain were mostly small in eastern and southern districts, but there was prolonged and sometimes heavy rain over northern and western Scotland, Northern Ireland, northwest England and Wales. On the 4th, 61mm of rain fell at Capel Curig (Caernarfon), 59mm at Shap (Cumbria), and 53mm at Tyndrum (Stirlingshire), and a further 55mm fell at Tyndrum on the 5th. Rainfall across Northamptonshire and at Pitsford was slight by comparison with just 2.9mm recorded on the 3rd and 1.8mm on the 4th. It was generally warm on the 1st and 2nd, and very warm on the 6th with temperatures widely in excess of 20°C. At Pitsford the daytime maximum reached 21.3C, although the highest was 23.9°C was recorded at Santon Downham in Norfolk.

With high pressure now in charge, the warm weather lasted until the 11th and most parts of the UK became dry and sunny and Northamptonshire was no exception. Afternoon highs were typically between 18 and 22°C, with a noteworthy 23.3°C recorded as far north as Fyvie (Aberdeenshire) on the 10th, but ground frost occurred widely during this period. The 12th was mainly sunny over England and Wales but much cooler, while Scotland and Northern Ireland had heavy showers and most districts were cool and cloudy over the next two days. It gradually became warmer again from the 15th onwards with temperatures climbing a little each day, and a spell of exceptional warmth and sunshine lasted from the 19th-25th, and a remarkable diurnal range of 16.4C was recorded at Pitsford on the 21st. The fine spell led up to the warmest April day on record. The warmest location was Wisley in Surrey recording 27.8°C, although 26.0C was recorded at Pitsford, beating the previous April record in 2003. However, the Wisley temperature was the highest April temperature recorded anywhere in Britain since 1949.

It became rather less warm on the 24th and 25th as winds swung round from the north with highest temperatures found along the south coast, and the 26th was a generally cloudy and rather cool day over the southern half of the country except along the south coast where some sites reported 12 consecutive days with 10hr or more bright sunshine between the 17th and 28th, and Southampton logged an aggregate of 143h sunshine during this spell. Across Northamptonshire sunshine amounts were rather varied. As the month came to a close, in common with many places, the county saw some fine sunny weather for the extended Bank Holiday weekend. Showers were forecast for the Royal Wedding (29th), but were confined to the overnight period. Despite the warmth during the sunshine, it did feel cold in the shade due to a brisk easterly breeze and overnight lows fell sharply.

Overall this was the warmest April in Northampton since 1997 (12.8C) and the driest since 2007 (1.6mm).

Air Temperatures    
The Highest Maximum: 26.0 C on 23rd
The Lowest Maximum: 12.4 C on 13th
The Highest Minimum: 11.2 C on 6th
The Lowest Minimum: 2.2 C on 13th
The Mean Maximum: 18.1 C  
The Mean Minimum: 7.2 C  
The Overall Mean: 12.7 C  
Difference from the Monthly Mean: +4.5 C  
    
Solar Radiation    
Maximum (at 0900): 611.0 W/m^2 on 27th
Mean (at 0900): 338.7 W/m^2  
    
Relative Humidity:    
Highest Relative Humidity (at 0900): 92.0 % on 3rd
Lowest Relative Humidity (at 0900): 46.2 % on 25th
Mean Relative Humidity (at 0900): 77.1 %  
    
Dew Point:    
The Highest Dew Point (0900): 14.1 C on 23rd
The Lowest Dew Point (at 0900): 3.2 C on 12th
The Mean Dew Point (at 0900): 8.2 C  
    
Rainfall:    
Total: 7.4 mm  
Percentage of the Monthly Mean: 16.4 %  
Duration: 6.2 hrs  
Highest 24 hour fall (0900 to 0900): 2.9 mm on 3rd
Rain Days (>/=0.2mm): 6   
Wet Days (>/=1.0mm): 3   
    
Sunshine:    
Total Duration of Bright Sunshine: 201.5 hrs  
Sunniest day: 12.5 hrs on 8th
No. of days without sunshine: 3   
Percentage of the Monthly Mean: 132.3 %  
Cloud cover (mean at 0900): 4.2 oktas 52.5 %
    
Pressure (reduced to sea level):    
The Highest Pressure (at 0900): 1030.8 mb on 12th
The Lowest Pressure (at 0900): 1006.3 mb on 2nd
Mean Pressure (at 0900): 1020.7 mb  
    
Winds    
Run of wind (mean over 24 hrs): 132.2 miles  
Mean daily wind speed: 7.2 mph  
Run of wind (cumulative): 3965.5 miles  
Highest Maximum Gust: 33 mph on 11th
No. of gusts of 50mph or more: 0   
Highest wind strength (at 0900): 20.8 mph on 2nd
Mean wind strength (at 0900): 10.1 mph  
    
Winds from the Following Directions:    

N 5 NE 4 E 5 SE 2 S 5 SW 3 W 0 NW 6 Calm 0
    
Concrete     
Lowest Concrete Minimum: 2.0 C on 4th
Mean Concrete Minimum: 7.0 C  
    
Evaporation    
Piche 93.6 ml  
    
Days with:    
Thunder: 1   
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.