Rainfall

The flow in the River Ver is dependent on rainfall to recharge the aquifer, from which water is pumped to supply the needs of the district (see Aquifer page).  Recharge largely happens in the winter and early spring; any rainfall during the summer has little effect as surface water evaporates and is used up by growing vegetation. Although after heavy rains, at any time of year, the run-off can cause short-term improvement in flow, it takes many weeks for any effect to be measured in aquifer levels or to have any long-term effect on the river.

It is therefore important for the Ver Valley Society to monitor rainfall figures regularly throughout the year and we do this with the help of Rothamsted Research Station (see tables below). 2008 was the wettest year since 2000. In 2009 rainfall was nearly 10% above average and as the Bow Bridge Pumping Station (see aquifer notes) was shut down until August good flows were recorded in the first half of that year and the aquifer came back to average values.

Subsequent rainfall in 2009 and 2010 generally fell below average but flows remained moderate. However poor winter rains in 2011 mean the river was exceptionally low by the end of 2011. However the total rainfall for 2012 was the highest ever recorded at Rothamsted and their records go back to 1870. Unusually the aquifer level increased over the summer months. At the end of 2012 it was over 3 metres above average and the river was flowing north of Redbourn.

2013 rainfall was just above average with storms in December and in 2014 January rainfall was highest monthly total ever recorded since Rothamsted started recording in 1870. That summer saw a very high aquifer and good flows as a result but the winter of 2014/2015 had poor rainfall and the subsequent dry warm summer and autumn meant the aquifer dropped to well below average and poor flows resulted. Early winter 2015 was very warm with only poor rainfall but better rainfall at the beginning of 2016 helped some recovery of the aquifer and reasonable flows have been maintained through the summer after a wet June. 2017 has been relatively dry particuarly in the winter months and with the very low aquifer the Ver has been dry for many months north of Redbourn.

 

See rainfall figures below. We are grateful to Rothamsted Research who supply these figures to the Society each month. If you wish to use these figures you should seek permission from  Rothamsted Research.

 


Rainfall 2017

Month 2017 Actual rainfall  Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 70.2 70.0 0.2 100.3%
February 38.7 50.1 -11.4 77.2%
March 40.4 50.8 -10.4 79.5%
April 10.9 55.1 -44.2 19.8%
May 70.5 54.7 15.8 128.9%
June 39.1 53.2 -14.1 73.5%
July 72.6 49.9 22.7 145.5%
August 66.6 63.7 2.9 104.5%
September 86.9 57.6 29.3 150.8%
October 31.2 81.8 -50.6 38.1%
November        
December        
         
TOTALS 527.1 586.9 -59.8 89.8%

 

 


Rainfall 2016

 

Month 2016 Actual rainfall  Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 92.3 70.0 22.3 131.9%
February 46.9 50.2 -3.3 93.5%
March 84.3 50.8 33.5 166.0%
April 62.0 55.0 7.0 112.6%
May 39.4 54.7 -15.3 72.0%
June 84.8 53.2 31.6 159.3%
July 27.1 49.9 -22.8 54.3%
August 30.1 63.7 -33.6 47.3%
September 70.3 57.6 12.7 122.0%
October 30.1 81.7 -51.6 36.9%
November 85.7 76.7 9.0 111.8%
December 26.2 69.5 -43.3 37.7%
         
TOTALS 679.2 732.9 -53.7 92.7%

 


 

Rainfall 2015

 

Month 2015 Actual rainfall  Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 81.9 70.0 11.9 117.1%
February 54.6 50.2 4.4 108.8%
March 26.1 50.8 -24.7 51.4%
April 31.0 55.1 -24.1 56.3%
May 68.4 54.7 13.8 125.2%
June 26.7 53.3 -26.6 50.1%
July 132.6 49.9 82.7 265.8%
August 83.2 63.7 19.5 130.6%
September 45.5 57.7 -12.2 78.9%
October 64.6 81.6 -17.0 79.1%
November 84.0 76.6 7.4 109.7%
December 81.8 69.5 12.3 117.7%
         
TOTALS 780.4 732.9 47.5 106.5%

 

 


 

Rainfall 2014

 

Month 2014 Actual rainfall  Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 176.2 69.9 106.3 252.1%
February 141.9 50.1 91.8 283.2%
March 28.2 50.8 -22.6 55.5%
April 31.5 54.1 -22.6 58.3%
May 82.8 54.7 28.1 151.5%
June 30.5 53.3 -22.8 57.3%
July 36.9 49.9 -13.0 73.9%
August 113.3 63.7 49.6 177.8%
September 14.8 57.6 -42.8 25.7%
October 95.7 81.7 14.1 117.2%
November 108.2 76.6 31.6 141.2%
December 64.0 69.6 -5.6 92.0%
         
TOTALS 924.0 731.8 192.2 126.3%

 

 


 

Rainfall 2013

 

Month 2013 Actual rainfall  Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 62.8 70.0 -7.2 89.8%
February 43.4 50.1 -6.7 86.6%
March 83.1 50.8 32.3 163.6%
April 32.8 55.1 -22.3 59.5%
May 56.0 54.7 1.2 102.4%
June 24.6 53.3 -28.7 46.2%
July 47.4 50.1 -2.5 94.6%
August 57.5 63.7 -6.2 90.2%
September 50.2 57.6 -7.4 87.2%
October 108.8 81.7 27.1 133.1%
November 59.5 76.6 -17.1 77.6%
December 123.1 69.5 53.6 177.1%
         
TOTALS 749.2 733.1 16.1 102.2%

 

 


Rainfall 2012

 

Month 2012
Actual rainfall Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January
58.0 70.0 -12.0 82.9%
February
24.7 50.3 -25.6 49.1%
March
34.7 50.8 -16.1 68.3%
April
168.6 55.0 113.6 306.4%
May
52.6 54.7 -2.1 96.2%
June
166.5 53.3 113.2 312.4%
July
128.4 49.8 78.6 257.7%
August
54.9 63.7 -8.8 86.2%
September
40.4 57.7 -17.3 70.1%
October
115.8 81.7 34.1 141.8%
November
100.4 76.6 23.8 131.1%
December
114.2 69.5 44.7 164.2%
 
       
TOTALS
1059.2 733.1 326.1 144.5%

 

 


 

Rainfall 2011

Month 2011
Actual rainfall  Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January
84.6 70.0 14.6 120.9%
February
56.8 50.1 6.7 113.3%
March
10.0 50.8 -40.8 19.7%
April
5.2 55.1 -49.9 9.4%
May
23.6 54.7 -31.1 43.2%
June
83.0 53.3 29.7 155.8%
July
44.6 49.9 -5.3 89.4%
August
81.2 63.7 17.5 127.4%
September
38.4 57.6 -19.2 66.6%
October
25.2 81.7 -56.5 30.9%
November
36.4 76.6 -40.2 47.5%
December
82.4 69.5 12.9 118.5%
 
       
TOTALS
571.4 732.9 -161.5 78.0%

 


 

Rainfall 2010

 

Month 2010
Actual rainfall (2010) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January
47.3 69.7 -22.4 67.9%
February
77.2 48.8 28.4 158.2%
March
45.2 53.9 -8.7 83.8%
April
18.7 53.4 -34.7 35.0%
May
38.4 49.7 -11.3 77.3%
June
23.5 60.2 -36.7 39.0%
July
31.6 42.1 -10.5 75.1%
August
127.6 53.5 74.1 238.3%
September

59.7

61.0

-1.3

97.9%
October
84.9 74.7 10.2 113.7%
November
54.9 66.3 -11.4 82.8%
December
35.3 70.1 -34.8 50.4%
     
TOTALS
644.3 703.4 -59.1 91.6%

 

Rainfall 2009

 

Month 2009
Actual rainfall (2009) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January
70.4 69.7 0.7 101.0%
February
73.9 48.8 25.1 151.4%
March
37.3 53.9 -16.6 69.2%
April
46.7 53.5 -6.8 87.3%
May
24.8 49.7 -24.9 49.9%
June
68.1 60.2 7.9 113.1%
July
73.3 42.1 31.2 174.1%
August
63.4 53.7 9.7 118.1%
September
15.9 61.0 -45.1 26.1%
October
39.1 74.7 -35.6 52.4%
November
146.1 66.2 79.9 220.6%
December
105.2 70.1 35.1 150.0%
   
TOTALS
764.2 703.6 60.6 108.6%

 

Rainfall 2008

 

Month 2008
Actual rainfall (2008) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January
103.20 69.70 33.50 148.1%
February
21.90 48.80 -26.90 44.9%
March
108.50 53.90 54.60 201.3%
April
53.50 53.50 0.00 100.0%
May
87.00 49.70 37.30 175.1%
June
35.30 60.20 -24.90 58.6%
July
90.3 42.00 48.30 215.0%
August
107.8 53.70 54.10 200.7%
September
66.2 61.00 5.20 108.5%
October
74.3 74.7 -0.40 99.5%
November
91.1 66.2 24.90 137.6%
December
42.0 70.1 -28.10 59.9%
   
TOTALS
881.10 703.50 177.60 125.2%

 

Rainfall 2007

 

Month 2007
Actual rainfall (2007) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January
91.60 69.70 21.90 131.4%
February
97.44 48.60 48.84 200.5%
March
57.60 53.90 3.70 106.9%
April
2.80 53.50 -50.70 5.2%
May
135.80 49.70 86.10 273.2%
June
72.40 60.20 12.20 120.3%
July
86.8 44.60 42.20 194.6%
August
64.6 53.90 10.70 119.9%
September
29.2 61.00 -31.80 47.9%
October
57.1 74.7 -17.60 76.4%
November
80.0 66.2 13.80 120.8%
December
67.1 70.1 -3.00 95.7%
   
TOTALS
842.44 706.10 136.34 119.3%

 

Rainfall 2006

 

Month 2006
Actual Rainfall (2006) Millimetres Average Rainfall Millimetres +/- mm Average Percent Average
January
29.20 69.70 -40.50 41.9%
February
41.40 48.80 -7.40 84.8%
March
49.50 53.90 -4.40 91.8%
April
51.00 53.50 -2.50 95.3%
May
89.00 49.70 39.30 179.1%
June
15.00 60.20 -45.20 24.9%
July
35.60 42.10 -6.50 84.6%
August
110.00 53.70 56.30 204.8%
September
54.20 61.00 -6.80 88.9%
October
105.00 74.70 30.30 140.6%
November
104.40 66.20 38.20 157.7%
December
95.00 74.10 20.90 128.2%
 
       
TOTALS
779.30 707.60 71.70 110.1%

 

Rainfall 2005

 

Month 2005
Actual rainfall (2005) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January
33.8 69.7 -35.9 48.5%
February
36.2 48.8 -12.6 74.2%
March
43.2 53.4 -10.2 80.9%
April
65.6 53.5 12.1 122.6%
May
44.4 49.7 -5.3 89.3%
June
44.0 60.2 -16.2 73.1%
July
39.0 42.1 -3.1 92.6%
August
58.6 53.7 4.9 109.1%
September
65.0 61.0 4.0 106.6%
October
88.4 74.7 13.7 118.3%
November
53.8 66.8 -13.0 80.5%
December
53.0 74.5 -21.5 71.1%
 
       
TOTALS
625.0 708.1 -83.1 88.3%

.. © River Ver 2011