PITSFORD HALL WEATHER STATION
NORTHAMPTON, UNITED KINGDOM

MONTHLY WEATHER REPORT - AUGUST 2001


Headline: A very warm period around mid-month, but generally 
unsettled with frequent and sometimes thundery breakdowns.

After a reasonably warm start with daytime maxima generally in 
the low to mid twenties, a cooling trend was observed from the 
6th associated with the close passage of an area of low pressure. 
Apart from the 1st, rain fell on a daily basis becoming particularly 
pronounced between the 6th and 9th. Some areas experienced some 
thundery conditions on the 6th, but it wasn't until the 8th and 
9th that thunderstorm activity was observed in Northamptonshire.  

From the 10th onwards temperatures gradually recovered eventually 
reaching the highest daytime maximum for August of 30.1C on the 
15th. Unsettled at first with occasional rain the skies became 
drier as the days wore on and some respectable sunshine totals 
were recorded from the 13th to the 15th. 

Another breakdown in the weather occurred from the 16th onwards. 
Again thunder was observed in many areas, although not recorded 
at Pitsford. Daytime maxima fell, although remained fairly 
respectable at the mid to low twenties. A gradual rise in 
atmospheric pressure from the 20th onwards brought mostly calm 
conditions with mean daily wind speeds on the 22nd and 23rd 
barely reaching 1mph. 

As the weather turned more humid from the 24th onwards and 
with the progression of a cold front eastwards over the next 
couple of days conditions were set for outbreaks of rain and 
some sharp thundery downpours. On the 25th 3.7mm of rain fell 
in a matter of minutes. With the passage of the front there 
was an inevitable downturn in the temperatures.

As the month came to a close, the recovery in pressure brought 
a brief dry and bright spell. However, developing low pressure 
over the North Sea maintained a north-westerly wind direction 
which kept the temperatures pegged down. Some light showers 
were also conveyed to the county on these winds on the 30th 
and 31st.



Climatological & Agromet Statistics - August 2001

Climatological Statistics - Pitsford Hall

Air Temperatures				
The Highest Maximum: 30.1C on 15th
The Lowest Maximum: 16.7C on 9th
The Highest Minimum: 17.3C on 15th
The Lowest Minimum: 8.1C on 28th

The Mean Maximum: 22.4C
The Mean Minimum: 12.6C
The Overall Mean: 17.5C
Difference from the Monthly Mean: +1.2C
				
Relative Humidity:				
Highest Relative Humidity (at 0900): 98.0% on 6th
Lowest Relative Humidity (at 0900): 59.6% on 27th
Mean Relative Humidity (at 0900): 82.2%
    
Dew Point:				
The Highest Dew Point (at 0900): 18.0C on 24th
The Lowest Dew Point (at 0900): 9.6C on 27th
The Mean Dew Point (at 0900): 14.2C
				
Rainfall:				
Total: 60.9 mm
Difference from the Monthly Mean: 125.1%
Duration: 28.8hrs
Highest 24-hour fall (from 0900): 13.1mm on 8th
Rain Days (>/=0.2mm): 17
Wet Days (>/=1.0mm): 14
Lowest pH: 6.37 on 11th
			
Sunshine:				
Total Duration of Bright Sunshine: 190.7hrs
Sunniest day: 11.9 hrs on 27th
Sunless days: 3
Cloud cover (mean at 0900): 5.9 oktas (73.8%)
				
Pressure (reduced to sea level):				
The Highest Pressure: 1026.1mb on 1st
The Lowest Pressure: 998.4mb on 7th
Mean Pressure (recorded at 0900): 1014.3mb
		
Winds:				
Run of wind (mean over 24 hrs): 58.6 miles
Mean daily wind speed: 3.2mph
Highest 24-hour Wind Speed: 6.3mph on 31st
Run of wind (to date): 1817.2 miles
Highest Maximum Gust: 27mph on 31st
Highest wind strength (at 0900): 17.3mph on 16th
Mean wind strength (at 0900): 7.0mph
		
Winds from the Following Directions:				
N 0, NE 3, E 1, SE 7, S 5, SW 2, W 3, NW 6, Calm 4
	
Days with:				
Thunder: 3: 8th, 9th & 25th
Hail less than 0.5mm: 1: 25th
Hail greater than/equal to 0.5mm: 0   
Snow or snow & rain: 0
Snow lying: 0
Fog: 0
Air Frost: 0
Duration of Air Frost: 0 hrs
Ground Frost: 0

Evaporation: 

We have decided to resume calculation of evaporation totals 
using the Hook-gauge evaporimeter on a daily basis. 

The total evaporation computed since resumption on the 21st 
was 26.85mm.	

	
Agro-Meteorological Statistics - Pitsford Hall Agromet Site 
(Brixworth)
				
Ground Temperatures:			 	
Lowest Grass Minimum: 6.2C on 28th
Mean Grass Minimum: 11.0C
Lowest Concrete Minimum: 9.3C on 10th
Mean Concrete Minimum: 13.3C
Lowest Bare Earth Minimum: 9.3C on 10th
Mean Bare Earth Minimum: 13.0C
				
Soil/Earth Temperatures (under grass):		 		
Surface mean: 14.9C
5cm mean: 15.4C
10cm mean: 15.7C  
20cm mean: 17.0C  
30cm mean: 17.5C
40cm mean: 17.7C
50cm mean: 18.2C
100cm mean:  17.5C
	

				
Climatological observations made at 0900 UTC. 
Agro-meteorological observations made at 0700 UTC. 
Averages refer to the period 1971-2000.



Permission to use this data in a commercial form must be
sought in writing from the station manager.