Yearly Weather Summaries

Data supplied from the Rothamsted Meteorological Station (Harpenden)

Change of rain gauge and the effect on rainfall capture and data presented in Monthly Weather Summaries.

Rainfall up until 2004 was measured manually using a cylindrical rain gauge of five inch diameter (5") within a turf-wall enclosure to reduce wind turbulence. In 2004 the Met Station at Rothamsted was automated and the 5" rain gauge replaced with an aerodynamically shaped tipping bucket rain gauge of ten inch diameter (type ARG100) within the enclosure. The manufacturers of the ARG100 state that "the ARG100 raingauge typically captures over 5% more rainfall than most traditionally-shaped cylindrical gauges due to its unique aerodynamic shape and reduced evaporation-loss properties". This has been found to be the case at Rothamsted. When we have compared the ARG100 with the 5" we get a difference of approximately ten percent over an eight year period (2004 to 2011).

We have therefore decided not to correct rainfall data but to advise that this difference exists. This does however mean that the 30 year average rainfall data are to be considered for use as guidance only.

Table of warnings about 30 year rainfall averages
 
30 Year Average
(Gauge used)
Associated Weather Summary Table Status
1971 to 2000 (5" only) 2001 to 2010 up to 2003 - OK
2004 onwards - guidance only
1981 to 2010 (5" and ARG100) 2011 onwards guidance only

| 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | previous summaries


Rothamsted Research (Harpenden)
The weather : Monthly Summary : 2019
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 83.6 (+21.53) 6.2 (-0.54) 0.6 (-0.55) 17 3.3 5.8 34.8 (-35.17) 10
February 137.7 (+57.44) 10.9 (+3.97) 1.6 (+0.62) 21 3.8 5.4 43.2 (-6.94) 17
March 148.0 (+33.11) 11.4 (+1.50) 4.3 (+1.67) 11 6.4 7.8 60.4 (+9.60) 19
April 191.6 (+30.40) 13.9 (+1.30) 3.6 (-0.41) 16 8.4 9.3 13.2 (-41.86) 13
May 206.4 (+11.81) 16.3 (+0.24) 6.3 (-0.52) 9 12.4 12.0 42.8 (-11.89) 15
June                        
July                        
August                        
September                        
October                        
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December                        
                         
Year                        
                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page

Rothamsted Research (Harpenden)
The weather : Monthly Summary : 2018
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 64.9 (+2.83) 8.2 (+1.46) 2.2 (+0.96) 15 3.8 5.5 76.1 (+6.15) 23
February 116.6 (+36.29) 5.2 (-1.72) -0.7 (-1.58) 23 2.0 4.5 48.4 (-1.74) 16
March 87.4 (-27.51) 8.1 (-1.76) 1.7 (-0.98) 21 3.8 5.2 78.5 (+27.70) 25
April 128.2 (-33.05) 14.0 (+1.33) 6.7 (+2.63) 3 9.5 9.6 74.8 (+19.77) 17
May 267.2 (+72.55) 18.7 (+2.59) 7.9 (+1.00) 8 13.6 12.9 61.9 (+7.24) 13
June 266.2 (+68.03) 21.5 (+2.40) 10.9 (+1.11) 0 17.6 16.2 3.7 (-49.61) 7
July 294.4 (+89.18) 26.1 (+4.29) 13.8 (+1.92) 0 20.9 18.4 15.1 (-34.82) 6
August 172.9 (-23.35) 22.3 (+0.74) 12.5 (+0.69) 0 17.4 17.7 64.0 (+0.27) 13
September 188.2 (+44.77) 19.0 (+0.67) 9.2 (-0.69) 5 13.6 15.3 51.0 (-6.63) 12
October 141.1 (+29.34) 14.9 (+0.83) 6.9 (-0.21) 8 10.0 12.5 71.0 (-10.68) 18
November 80.9 (+10.11) 10.8 (+1.06) 4.9 (+1.13) 7 6.8 9.2 63.8 (-12.83) 21
December 57.0 (+3.21) 9.3 (+2.38) 3.7 (+2.01) 12 5.6 7.5 75 (+5.48) 21
                         
Year 1864.7 (+272.39) 14.8 (+1.19) 6.6 (+0.67) 102 10.4 11.2 683.3 (-49.70) 192
                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page

Rothamsted Research (Harpenden)
The weather : Monthly Summary : 2017
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 77.2 (+15.19) 6.3 (-0.38) -0.2 (-1.40) 19 2.2 4.1 70.2 (+0.21) 23
February 62.8 (-17.48) 8.5 (+1.59) 3.2 (+2.29) 15 4.6 5.6 38.7 (-11.40) 18
March 139.9 (+24.97) 12.7 (+2.76) 5.0 (+2.33) 15 8.0 7.8 40.4 (-10.42) 21
April 197.4 (+36.17) 13.8 (+1.20) 4.2 (+0.13) 17 10.2 9.6 10.9 (-44.19) 14
May 185.1 (-9.57) 17.7 (+1.65) 8.6 (+1.79) 2 13.8 12.7 70.5 (+15.82) 16
June 229.1 (+30.91) 21.5 (+2.38) 12.0 (+2.25) 1 18.5 16.7 39.1 (-14.12) 12
July 187.4 (-17.77) 21.8 (+0.00) 13.2 (+1.31) 0 18.2 17.6 72.6 (+22.69) 16
August 170.2 (-26.04) 20.2 (-1.39) 11.8 (-0.03) 0 16.3 16.7 66.6 (+2.89) 14
September 116.9 (-26.44) 17.3 (-0.94) 9.8 (-0.17) 1 13.3 15.0 86.9 (+29.29) 23
October 87.4 (-24.30) 15.4 (+1.37) 9.1 (+1.99) 3 11.5 13.5 31.2 (-50.51) 19
November 92.0 (+21.21) 9.6 (-0.09) 3.5 (-0.28) 15 6.5 11.8 53.5 (-23.09) 22
December 57.4 (+3.57) 7.2 (+0.35) 1.8 (+0.17) 19 4.0 6.0 110.8 (+41.25) 24
                         
Year 1602.7 (+10.41) 14.3 (+0.71) 6.8 (+0.86) 107 10.5 11.3 691.4 (-41.58) 222
                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page

Rothamsted Research (Harpenden)
The weather : Monthly Summary : 2016
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 64.5 (+2.46) 8.1 (+1.36) 1.8 (+0.63) 16 4.3 6.5 92.3 (+22.34) 25
February 111.5 (+31.19) 8.0 (+1.09) 1.6 (+0.67) 18 3.6 5.9 46.9 (-3.27) 18
March 133.4 (+18.45) 9.2 (-0.65) 1.8 (-0.92) 18 4.4 6.2 84.3 (+33.52) 16
April 167.6 (+6.37) 11.9 (-0.73) 3.5 (-0.52) 12 7.2 8.8 62.0 (+6.96) 24
May 197.0 (+2.40) 17.4 (+1.34) 7.9 (+0.99) 7 13.0 12.4 39.4 (-15.30) 11
June 141.0 (-57.17) 19.0 (-0.11) 11.2 (+1.45) 0 15.8 15.5 84.8 (+31.58) 22
July 210.3 (+5.09) 22.2 (+0.43) 12.8 (+0.89) 0 18.3 17.3 27.1 (-22.80) 16
August 217.6 (+21.38) 22.7 (+1.17) 12.9 (+1.02) 0 17.8 17.1 30.1 (-33.58) 12
September 128.0 (-15.44) 20.4 (+2.10) 12.2 (+2.29) 0 15.8 16.5 70.3 (+12.68) 16
October 104.0 (-7.73) 14.2 (+0.18) 7.4 (+0.30) 4 10.3 12.4 30.1 (-51.55) 22
November 91.1 (+20.40) 8.8 (-0.94) 2.6 (-1.24) 11 5.8 8.6 85.7 (+9.04) 21
December 68.7 (+14.91) 8.7 (+1.77) 2.1 (+0.40 18 4.8 6.7 26.2 (-43.28) 24
                         
Year 1634.6 (+42.31) 14.2 (+0.58) 6.5 (+0.50) 104 10.1 11.2 679.3 (-53.66) 227
                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page

Rothamsted Research (Harpenden)
The weather : Monthly Summary : 2015
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 90.6 (+28.51) 7.5 (+0.76) 0.9 (-0.32) 17 5.0 7.2 81.9 (+11.93) 25
February 85.6 (+5.31) 6.7 (-0.21) 0.8 (-0.17) 18 2.4 4.1 54.6 (+4.42) 21
March 158.9 (+43.99) 10.2 (+0.27) 2.9 (+0.27) 15 5.4 6.2 26.1 (-24.67) 16
April 231.7 (+70.50) 14.5 (+1.85) 4.2 (+0.13) 15 8.8 9.6 31.0 (-24.05) 14
May 203.4 (+8.79) 15.6 (-0.53) 7.0 (+0.12) 6 11.9 12.3 68.4 (+13.75) 19
June 227.9 (+29.77) 19.5 (+0.33) 9.2 (-0.58) 3 15.5 14.7 26.7 (-26.55) 12
July 210.4 (+5.20) 21.4 (-0.40) 11.7 (-0.15) 0 16.4 16.9 132.6 (+82.71) 17
August 141.2 (-55.00) 20.5 (-1.10) 12.1 (+0.29) 0 16.4 16.6 83.2 (+19.49) 15
September 154.4 (+10.96) 16.9 (-1.38) 8.45 (-1.47) 4 12.3 14.7 45.5 (-12.18) 20
October 94.2 (-17.50) 14.2 (+0.16) 7.8 (+0.71) 5 10.4 12.4 64.6 (-17.04) 21
November 46.4 (-24.30) 12.3 (+2.57) 6.6 (+2.79) 5 8.7 10.9 84.0 (+7.40) 26
December 48.2 (-5.60) 12.5 (+5.56) 7.3 (+5.66) 3 8.4 9.5 81.8 (+12.29) 24
                         
Year 1692.9 (+100.64) 14.3 (+0.66) 6.6 (+0.59) 91 10.1 11.1 780.5 (+47.50) 230
                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page


 
Rothamsted Research
The weather : Monthly Summary : 2014
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 59.9 (-2.10) 8.5 (+1.83) 2.9 (+1.66) 9 4.4 5.8 176.2 (+106.18) 28
February 93.1 (+12.88) 9.0 (+2.07) 3.2 (+2.31) 13 4.2 5.5 141.9 (+91.80) 23
March 180.8 (+65.91) 12.7 (+2.84) 3.4 (+0.73) 12 5.8 7.2 28.2 (-22.57) 16
April 162.7 (+1.51) 14.8 (+2.19) 6.1 (+2.12) 3 9.8 10.3 31.5 (-23.54) 14
May 173.6 (-20.98) 16.5 (+0.41) 8.3 (+1.39) 2 12.7 13.0 82.8 (+28.14) 18
June 227.7 (+29.53) 20.2 (+1.01) 10.6 (+0.88) 0 16.9 16.1 30.5 (-22.77) 14
July 233.4 (+28.25) 23.9 (+2.11) 13.3 (+1.40) 0 19.1 17.8 36.9 (-13.00) 14
August 168.9 (-27.38) 19.9 (-1.59) 11.4 (-0.44) 0 16.1 16.7 113.3 (+49.59) 22
September 118.9 (-24.46) 20.1 (+1.85) 11.6 (+1.71) 0 15.6 15.9 14.8 (-42.81) 13
October 98.9 (-12.84) 16.0 (+1.97) 9.8 (+2.63) 4 12.0 13.5 95.7 (+14.05) 24
November 56.3 (-14.48) 11.3 (+1.53) 5.9 (+2.06) 9 8.2 10.4 108.2 (+31.57) 27
December 94.7 (+40.85) 8.1 (+1.20) 2.1 (+0.41) 17 4.6 6.9 64.0 (-5.57) 24
                         
Year 1669.0 (+76.69) 15.1 (+1.45) 7.4 (+1.40) 69 10.8 11.6 924.1 (+191.13) 237
                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page

Rothamsted Research (Harpenden)
The weather : Monthly Summary : 2013
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 44.8 (-17.23) 4.9 (-1.78) 0.5 (-0.70) 18 3.4 5.2 62.8 (-7.17) 16
February 86.1 (+5.81) 5.2 (-1.75) 0.2 (-0.74) 16 2.0 4.1 43.4 (-6.74) 18
March 72.9 (-42.00) 5.2 (-4.71) -0.16 (-2.83) 19 3.3 4.2 83.1 (+32.30) 15
April 193.7 (+32.53) 12.2 (-0.45) 3.0 (-1.05) 13 6.4 6.8 32.8 (-22.29) 15
May 183.2 (-11.44) 14.8 (-1.32) 6.2 (-0.72) 6 10.9 10.9 56.0 (+1.28) 15
June 185.3 (-12.89) 18.0 (-1.10) 9.3 (-0.45) 1 14.5 13.6 24.6 (-28.69) 9
July 277.3 (+72.09) 24.5 (+2.71) 12.8 (+0.93) 0 19.5 17.2 47.4 (-2.48) 12
August 191.2 (-5.04) 22.1 (+0.49) 12.7 (+0.88) 0 17.4 17.3 57.5 (-6.23) 14
September 122.7 (-20.67) 17.8 (-0.53) 9.7 (-0.20) 0 13.5 15.0 50.2 (-7.39) 21
October 84.7 (-27.05) 15.3 (+1.21) 9.3 (+2.15) 2 11.5 13.1 108.8 (+27.07) 26
November 77.9 (+7.13) 8.9 (-0.85) 3.6 (-0.24) 9 5.9 8.7 59.5 (-17.13) 23
December 62.1 (+8.33) 9.1 (+2.22) 2.6 (+0.92) 16 4.8 6.7 123.1 (+53.60) 24
                         
Year 1581.9 (-10.43) 13.2 (-0.49) 5.8 (-0.17) 100 9.4 10.2 749.1 (+16.13) 208
                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page

Rothamsted Research (Harpenden)
The weather : Monthly Summary : 2012
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 82.2 (+20.18) 8.4 (+1.75) 2.5 (+1.26) 13 4.2 6.1 58.0 (-11.97) 20
February 109.3 (+29.03) 6.4 (-0.50) 0.1 (-0.85) 15 2.6 4.1 24.7 (-25.44) 8
March 193.5 (+78.61) 12.8 (+2.94) 3.1 (+0.40) 22 6.1 7.6 34.7 (-16.13) 16
April 150.1 (-11.14) 11.5 (-1.11) 3.3 (-0.69) 14 8.1 8.9 168.6 (+113.57) 25
May 175.6 (-19.06) 16.1 (+0.05) 7.9 (+1.02) 4 11.8 11.9 52.6 (-2.08) 14
June 144.9 (-53.31) 17.6 (-1.51) 10.0 (+0.27) 3 14.2 14.6 166.5 (+113.21) 22
July 172.3 (-32.86) 19.8 (-1.96) 11.6 (-0.25) 0 16.4 16.8 128.4 (+78.57) 23
August 176.5 (-19.77) 21.8 (+0.18) 12.8 (+0.91) 0 17.2 17.4 54.9 (-8.82) 16
September 179.6 (+36.20) 18.3 (+0.01) 8.4 (-1.53) 1 13.3 14.9 40.4 (-17.27) 15
October 86.0 (-25.71) 12.7 (-1.36) 6.6 (-0.47) 8 9.3 12.0 115.8 (+34.13) 26
November 76.9 (+6.91) 9.4 (-0.32) 3.6 (-0.23) 13 5.8 8.6 100.4 (+23.79) 12
December 68.2 (+14.40) 7.5 (+0.64) 1.4 (-0.24) 15 4.2 5.3 114.2 (+44.67) 26
                         
Year 1615.0 (+22.68) 13.5 (-0.10) 5.9 (-0.03) 108 9.3 10.7 1059.2 (+326.23)

233

                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page

Rothamsted Research (Harpenden)
The weather : Monthly Summary : 2011
(Departure from the 30 year means (1981 - 2010) in brackets)
 
 
  Sunshine Mean Temperatures Rainfall
    Maximum Minimum Ground Frost * 10cm Under Bare Soil 30cm Under Grass Total Duration
  Hours ( ) oC ( ) oC ( ) no. oC oC mm ( ) days**
January 45.4 (-16.60) 6.0 (-0.68) 1.6 (+0.40) 16 3.3 4.6 86.4 (+14.63) 21
February 48.7 (-31.56) 8.8 (+1.89) 3.6 (+2.72) 8 4.8 5.6 56.8 (+6.66) 21
March 149.6 (+34.68) 10.7 (+0.85) 2.4 (-0.32) 15 5.1 6.2 10.0 (-40.80) 12
April 234.4 (+73.14) 17.6 (+4.98) 6.7 (+2.67) 4 10.4 10.8 5.2 (-49.86) 4
May 237.6 (+43.01) 17.4 (+1.32) 7.6 (+0.72) 4 13.1 12.8 23.6 (-31.09) 11
June 214.3 (+16.13) 19.0 (-0.14) 9.6 (-0.21) 1 15.0 14.7 83.0 (+29.74) 16
July 171.2 (-33.98) 19.9 (-1.83) 10.9 (-1.02) 0 16.2 16.1 44.6 (-5.27) 14
August 141.2 (-55.04) 19.9 (-1.67) 11.7 (-0.14) 0 15.8 16.3 81.2 (+17.47) 20
September 160.3 (+16.88) 19.6 (+1.28) 11.1 (+1.14) 0 14.0 15.1 38.4 (-19.22) 19
October 143.2 (+31.46) 16.7 (+2.60) 9.0 (+1.95) 4 11.6 13.2 25.2 (-56.47) 17
November 68.8 (-1.92) 12.4 (+2.66) 6.2 (+2.44) 4 8.9 10.9 36.4 (-40.19) 23
December 74.5 (+20.66) 8.6 (+1.71) 2.82 (+1.16) 11

4.5

6.8 82.4 (+12.88)

23

                         
Year 1689.1 (+96.86) 14.7 (+1.08) 6.9 (+0.95) 67 10.2 11.1 571.5 (-161.51)

201

                         
* Number of nights grass minimum below 0.0 oC
** Number of days rain was 0.2 mm or more Top of Page