Royston (Iceni) Weather Station

Daily Weather Observations - April 2013

(All Times GMT)

Date Max. Temp. (°C) 09/09h Min. Temp. (°C) 09/09h Grass Min. Temp. (°C) 21/09h Earth (30cms) Temp. (°C) 09h Sun (Hours) 00/00h R'fall (MM) 09/09h Wind Dir'n 09h Mean Wind Speed (MPH) 00/00h Max. Gust Speed (MPH) 00/00h Cloud Cover (Oktas) 09h Mean MSL Air Pressure (mB) 00/00h Mean Rel. Humd. (%) 00/00h Mean Temp. (°C) 00/00h Fog (vis. <1000m @ 09h) Fog (vis. <200m @ 09h) Snow or Rain and Snow 00/00h Snow Lying @ 09h (>50% cover) Hail 00/00h Thunder 00/00h Date
1 5.1 -0.7 -4.5 3.8 2.9 0.0 NE 5.3 22 8 1012.1 73.5 1.5 0 0 1 0 0 0 1
2 8.4 -4.4 -9.5 3.5 12.5 0.0 NE 5.8 23 2 1015.6 67.4 1.7 0 0 0 0 0 0 2
3 6.8 -3.1 -9.0 3.8 4.7 TR NE 7.3 30 7 1017.8 73.7 1.5 0 0 0 0 0 0 3
4 3.8 -1.5 -5.5 3.7 1.1 0.0 NE 8.2 31 8 1014.8 75.7 1.3 0 0 1 0 0 0 4
5 9.5 -0.3 -3.6 3.5 6.1 0.0 NE 8.2 30 8 1016.1 69.7 3.4 0 0 0 0 0 0 5
6 11.5 -2.5 -8.0 3.9 9.6 0.0 NE 3.5 14 5 1023.2 69.5 3.8 0 0 0 0 0 0 6
7 10.6 0.1 -2.5 4.5 8.8 0.0 SW 5.6 15 4 1018.7 62.8 4.8 0 0 0 0 0 0 7
8 10.4 -0.4 -3.5 5.0 3.3 TR NE 4.0 21 7 1005.4 71.3 4.4 0 0 0 0 0 0 8
9 10.8 -0.7 -4.4 5.1 1.1 0.0 E 3.8 20 8 997.7 78.6 5.5 0 0 0 0 0 0 9
10 13.2 1.7 0.9 5.8 6.3 2.4 NW 4.3 17 8 1002.7 77.2 6.4 0 0 0 0 0 0 10
11 8.8 4.4 4.3 6.9 0.7 6.4 NE 4.9 20 8 996.8 95.6 5.9 0 0 0 0 0 0 11
12 10.9 5.1 2.6 6.6 1.2 6.9 S 6.2 23 8 996.9 95.4 7.8 0 0 0 0 1 0 12
13 14.4 4.3 0.0 6.9 5.5 2.3 S 9.3 30 1 1009.7 88.7 9.2 0 0 0 0 0 0 13
14 20.3 10.9 9.2 8.0 8.3 TR S 12.9 34 3 1011.1 75.0 14.7 0 0 0 0 0 0 14
15 17.0 9.8 7.7 9.2 7.2 0.1 SW 11.0 31 2 1014.9 73.9 12.6 0 0 0 0 0 0 15
16 17.0 8.3 5.9 9.4 8.1 TR SW 11.3 34 7 1013.6 69.2 12.4 0 0 0 0 0 0 16
17 18.0 8.0 6.0 9.5 3.5 0.0 S 12.9 40 8 1011.6 78.1 13.0 0 0 0 0 0 0 17
18 15.3 8.1 6.1 9.8 8.4 0.2 SW 16.1 44 3 1010.8 65.2 10.5 0 0 0 0 0 0 18
19 11.8 6.5 4.4 9.6 2.2 0.1 NW 6.7 25 8 1025.4 77.5 7.9 0 0 0 0 0 0 19
20 14.3 -0.3 -4.2 8.9 13.7 0.0 E 3.6 15 0 1031.6 65.8 7.1 0 0 0 0 0 0 20
21 15.5 0.0 -4.5 9.0 9.4 0.0 SW 6.0 21 1 1019.8 65.3 8.4 0 0 0 0 0 0 21
22 14.5 5.0 3.0 9.5 5.3 0.0 SW 8.8 27 7 1014.2 76.1 10.3 0 0 0 0 0 0 22
23 20.5 8.8 6.6 10.0 12.4 0.0 W 6.6 20 4 1018.4 72.0 14.1 0 0 0 0 0 0 23
24 21.3 9.5 5.0 11.1 6.5 0.2 SW 6.9 24 6 1022.1 74.2 14.7 0 0 0 0 0 0 24
25 21.9 11.4 9.5 12.1 8.4 6.4 S 7.7 31 6 1019.1 75.8 15.5 0 0 0 0 0 0 25
26 12.8 6.2 6.1 12.5 4.6 0.2 NW 6.1 24 7 1013.9 77.1 8.3 0 0 0 0 0 0 26
27 11.5 3.4 0.2 11.5 5.3 0.4 N 5.5 24 7 1015.0 80.8 5.9 0 0 0 0 1 0 27
28 12.8 -0.1 -4.5 10.3 5.9 0.6 S 8.2 28 6 1014.8 69.9 7.2 0 0 0 0 0 0 28
29 15.0 5.1 2.6 10.4 9.6 0.0 W 9.2 25 7 1015.4 67.5 9.6 0 0 0 0 0 0 29
30 14.7 3.0 -1.4 10.4 10.4 0.0 N 4.7 20 5 1024.5 71.9 8.1 0 0 0 0 0 0 30
Total/Mean 13.3 3.5 0.5 7.8 192.9 26.2 X 7.3 X 5.6 1014.1 74.5 7.9 0 0 2 0 2 0 Total/Mean
*Diff./% -0.4 -1.3     124% 60%                           *Diff./%
Date Max. Temp. (°C) 09/09h Min. Temp. (°C) 09/09h Grass Min. Temp. (°C) 21/09h Earth (30cms) Temp. (°C) 09h Sun (Hours) 00/00h R'fall (MM) 09/09h Wind Dir'n 09h Mean Wind Speed (MPH) 00/00h Max. Gust Speed (MPH) 00/00h Cloud Cover (Oktas) 09h Mean MSL Air Pressure (mB) 00/00h Mean Rel. Humd. (%) 00/00h Mean Temp. (°C) 00/00h Fog (vis. <1000m @ 09h) Fog (vis. <200m @ 09h) Snow or Rain and Snow 00/00h Snow Lying @ 09h (>50% cover) Hail 00/00h Thunder 00/00h Date

Differences from average:

Differences from average shown in red. Reference periods used are as follows: Temperature 30 Years 1981/2010; rainfall 30 Years 1981/2010; sunshine 30 Years 1981/2010.

(*The differences from average quoted during the course of the month relate to the cumulative daily averages up to the date of the last observation, not the averages for the month as a whole)

Additional Data:

Rainfall Duration   N/A

Air Frost Duration    43.1 hours

Graphs and Charts:

Click on the following links to view this month's graphs and charts.....

1. Daily Maximum, Minimum & Grass Minimum Temperatures

2. Daily Maximum & Minimum Temperatures (with 30 Year Comparative Means)

3. Daily Earth (30 cms Depth) Temperature @ 0900 GMT  4. Daily Rainfall  5.  Daily Sunshine

6. Daily Maximum Gust & Mean Wind Speed  7. Daily Wind Direction @ 0900 GMT

8. Daily Mean MSL Air Pressure  9.  Daily Mean Relative Humidity   10. Thermograph 

11.  Barograph  12.  Hygrograph  13.  Anemograph  14.  Wind Direction

15. Rainfall Intensity & Duration

April 2013 Weather Review:

......and click on the link below for a text report of the April 2013 weather in Royston

April 2013 Weather Review

April (since 1973) at Royston (Iceni) Weather Station:

Mean daily maximum temperature (30 years 1981/2010) 13.7°C

Mean daily minimum temperature (30 years 1981/2010) 4.8°C

Highest temperature 27.1°C (23rd April 2011); lowest temperature -4.1°C (11th April 1978)

Lowest grass minimum temperature -9.4°C (4th April 1996)

Warmest April 2011 (Mean temperature 13.3°C); coldest April 1978 (Mean temperature 6.2°C)

Average April rainfall (30 years 1971/2000) 43.8 mm

Wettest April 1998 (Rainfall 120.7 mm); driest April 2007 (Rainfall 1.6 mm)

Wettest Day 9th April 1998 (Rainfall 32.0 mm);

Highest number of "rain days" (0.2 mm or more) 26 (1998); lowest number of "rain days" 3 (2007, 2011)

Highest number of days with thunder 7 (1998)

Highest number of air frosts 8 (1975)

Highest number of ground frosts 15 (1974, 1984)

Highest number of days with snow falling 5 (1975, 1986)

Highest number of days with snow lying (ground with more than 50% snow cover @ 0900 GMT) 2 (1978, 1983)

The lambing season is coming to an end in the region and here on the Ickworth estate (50 km ENE of Royston) the lambs are being rounded up by their mothers and hurriedly led off the hillside, across the brook, and onwards towards the lake area. The sheep appear to be in a very excited state and are emitting a cacophony of bleating as they rush forward at speed. They may have been disturbed by military re-enactors of the 95th Rifles of Napoleonic and Peninsular Wars fame who are battling the French a short distance away with the resulting loud explosions! If this is the reason for the 'stampede' then not all the sheep have been affected by the explosions as some remain on the hillside seemingly unfazed by the experience. This scene was observed at 1244 GMT on 6th April 2013 and a significant feature on view is the grass still in Winter condition, not having grown at all due to the unseasonably cold conditions of the Spring so far (at Royston the daily maximum temperature has not reached its 30 Year (1981/2010) mean since 6th March!). The maximum temperature on this day at Royston was 11.5°C and sunshine of 9.6 hours was recorded. The annual St George's Day Festival at Wrest Park (27 km SSW of Royston) held over the weekend of 20th & 21st April 2013 was once again a riot of colour and action (and sound!) attracting large numbers of visitors. In this picture taken at 1408 GMT on 20th April the Ermine Street Guard is about to demonstrate the training methods and manoeuvres of the first professional standing army, the Imperial Roman Army. The soldiers depicted would all have been citizens of Rome but the auxiliaries who accompanied them (not shown but with different colour shields and undertaking different roles) were not Romans but provided they stayed in the Army for 25 years they would then qualify for Roman citizenship. To have remained unscathed in the Army with the fearsome weapons employed at the time for this long period would have been some achievement! The Festival enjoyed abundant sunshine over the weekend with cloudless skies on the Saturday (at Royston this was the sunniest day of the month so far with 13.7 hours sunshine). The maximum temperature achieved at Royston on this day was 14.3°C. On the south side of Royston this is the Hertfordshire Way as it proceeds southwards past Flint Hall Farm and on towards The Grange, Hatchpen and the northern escarpment of the East Anglian Heights. Halfmoon Plantation can be seen on the left in the middle distance, and beyond this the countryside is transformed from arable use to stud farms and enclosures in the more level area before rising to the escarpment. As at this date in April 2013 (23rd) the month has been dry so far with rainfall running at only 60% of average and this is manifested in the dry soil and restricted crop growth in the field on the left. The exceptionally cold weather of March and early April has been a significant factor in holding back the germination and growth of Spring sown crops. However, milder conditions arrived in mid-April and on this day a maximum temperature of 20.5°C (5.4°C above the 30 Year (1981/2010) mean for 23rd April) was reached. At the time of the photograph (1355 GMT) the temperature was 18.7°C and the landscape was being refreshed by a W wind of mean speed 10 knots gusting to 17 knots. The day was essentially sunny, with 12.4 hours sunshine being recorded.

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(This page last updated 9th May 2013 2020 GMT)