Royston (Iceni) Weather Station

Daily Weather Observations - December 2004

(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 5.5 -1.0 -5.0 7.0 5.2 0.1 CALM 0.1 9 2 1010.5 95.3 2.2 0 0 0 0 0 0 1
2 7.5 2.2 -0.6 6.4 3.4 0.0 W 0.1 7 8 1014.6 94.9 3.9 0 0 0 0 0 0 2
3 7.6 -1.0 -4.5 6.4 4.4 0.0 SW 1.0 14 1 1022.9 95.1 3.3 0 0 0 0 0 0 3
4 10.2 6.2 4.9 6.4 2.2 0.0 SW 1.2 14 1 1029.4 92.6 8.0 0 0 0 0 0 0 4
5 10.3 6.4 4.8 7.1 0.0 0.0 W 2.2 21 8 1030.1 94.6 8.1 0 0 0 0 0 0 5
6 10.6 7.1 5.4 7.4 0.1 0.0 SW 3.1 25 8 1028.4 86.8 8.3 0 0 0 0 0 0 6
7 8.7 6.0 3.6 7.4 0.0 0.5 N 0.5 14 8 1030.3 94.8 7.6 0 0 0 0 0 0 7
8 8.9 7.1 6.5 7.8 0.0 0.0 SE 0.1 9 8 1031.7 96.7 7.6 0 0 0 0 0 0 8
9 7.3 2.3 -1.8 7.9 3.8 0.0 E 0.1 9 8 1025.9 93.1 5.0 1 1 0 0 0 0 9
10 6.0 2.6 2.5 7.4 0.0 0.0 SW 0.9 16 8 1024.4 90.3 3.4 0 0 0 0 0 0 10
11 8.9 2.5 0.0 7.0 4.1 TR S 0.1 12 8 1029.2 92.8 5.8 0 0 0 0 0 0 11
12 6.6 5.9 5.5 7.1 0.0 0.0 E 0.3 18 8 1029.3 92.2 5.4 0 0 0 0 0 0 12
13 5.6 0.7 0.6 7.0 0.0 0.0 SW 0.1 12 8 1028.7 92.1 1.4 0 0 0 0 0 0 13
14 10.0 1.4 1.4 6.7 0.1 TR S 4.7 25 8 1024.1 93.8 6.5 0 0 0 0 0 0 14
15 11.1 8.8 8.0 7.3 0.0 0.1 SW 6.4 30 8 1017.8 92.0 9.8 0 0 0 0 0 0 15
16 11.0 8.9 7.5 7.9 2.4 2.6 SW 8.4 35 7 1003.8 87.2 8.4 0 0 0 0 0 0 16
17 5.9 5.5 3.3 7.5 0.2 4.9 S 5.7 30 8 1000.0 88.7 4.7 0 0 0 0 0 0 17
18 7.0 1.7 -0.6 6.6 2.9 0.0 SW 4.4 28 5 1009.2 87.0 4.1 0 0 0 0 0 0 18
19 5.1 -0.1 -4.1 6.3 6.0 0.0 NE 0.8 16 1 1014.3 83.2 1.5 0 0 0 0 0 0 19
20 4.5 -1.5 -6.1 5.2 1.0 0.1 S 3.2 21 3 1021.0 86.8 1.7 0 0 0 0 0 0 20
21 7.5 0.7 -3.0 4.9 1.3 9.7 NW 1.4 18 8 1025.1 97.8 1.8 1 0 0 0 0 0 21
22 11.5 1.4 0.5 4.9 0.0 0.6 SW 7.5 41 8 1014.6 94.4 7.7 0 0 0 0 0 0 22
23 12.7 9.6 7.5 6.0 3.8 0.0 SW 10.1 36 0 1008.9 80.4 10.5 0 0 0 0 0 0 23
24 9.1 6.4 4.4 6.6 2.0 0.5 SW 8.8 37 3 1000.0 80.1 7.4 0 0 0 0 0 0 24
25 3.6 1.4 -0.6 6.3 4.1 0.0 SW 4.4 28 0 996.9 84.9 1.5 0 0 0 0 0 0 25
26 3.1 -2.1 -5.2 5.0 6.0 0.0 W 0.7 14 0 1011.7 91.7 -0.3 0 0 0 0 0 0 26
27 7.2 -1.6 -5.9 4.1 4.1 8.2 SW 3.2 32 0 1017.6 90.8 1.3 0 0 0 0 0 0 27
28 5.1 1.4 -0.9 3.9 6.3 0.0 W 6.4 35 0 1009.5 87.5 3.6 0 0 0 0 0 0 28
29 10.0 1.7 -1.4 3.8 1.4 TR W 4.1 23 1 1026.4 90.3 4.8 0 0 0 0 0 0 29
30 12.0 7.1 5.5 4.4 4.5 0.0 SW 6.0 28 5 1026.7 90.0 9.5 0 0 0 0 0 0 30
31 11.7 9.1 7.8 5.4 0.1 TR SW 5.4 32 7 1024.1 89.1 8.6 0 0 0 0 0 0 31
Total/Mean 8.1 3.4 1.3 6.3 69.5 27.3 X 3.3 X 5.0 1018.9 90.5 5.3 2 1 0 0 0 0 Total/Mean
*Diff./% +0.9 +0.4     146% 52%                           *Diff./%

Differences from average:

Differences from average shown in red. Reference periods used are as follows: Temperature 30 Years 1973/2002; rainfall 30 Years 1971/2000; sunshine 30 Years 1971/2000.

(*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  31.4 hours

Air Frost Duration  50.4 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. Sunshine Duration  16.  Rainfall Intensity & Duration

December 2004 Weather Review:

......and click on the link below for a text report of the December 2004 weather in Royston

December 2004 Weather Review

December (since 1972) at Royston (Iceni) Weather Station:

Mean day maximum temperature (30 years 1973/2002) 7.2°C

Mean night minimum temperature (30 years 1973/2002) 3.0°C

Highest temperature 15.1°C (2nd December 1985); lowest temperature -9.8°C (29th December 1995)

Lowest grass minimum temperature -14.6°C (13th December 1981)

Warmest December 1974 (Mean temperature 7.8°C); coldest December 1981 (Mean temperature 0.4°C)

Average December rainfall (30 years 1971/2000) 52.8 mm

Wettest December 1989 (Rainfall 122.4 mm); driest December 1991 (Rainfall 10.3 mm)

Wettest Day 27th December 1979 (Rainfall 31.5 mm);

Highest number of "rain days" (0.2 mm or more) 22 (1978); lowest number of "rain days" 8 (1991)

Highest number of days with thunder 3 (1989)

Highest number of air frosts 20 (1981)

Highest number of ground frosts 25 (1981)

Highest number of days with snow falling 10 (1981)

Highest number of days with snow lying (ground with more than 50% snow cover @ 0900 GMT) 23 (1981)

This tourist sign (as seen in bright early morning sunshine on 3rd December 2004) greets road users travelling south-westwards on the A505 Royston by-pass at its junction with the A10 trunk road just north of the town. The town of Royston grew up around the intersection of the Roman Ermine Street and the ancient Icknield Way after the Norman conquest in 1066. It has a marked tourist trail indicated by pavement studs and blue plaques on places of interest. One of these is King James Palace, a residence of King James VI of Scotland who was attracted to Royston after stopping here on his journey to London in 1603 to succeed to the English Crown and become also King James I of England.  Soon after this photograph was taken to the SE of  Royston (with the village of Barley just over the horizon) on 18th December 2004 at 0942 GMT continuous sunshine commenced and lasted until noon. Apart from a several brief sunny spells shortly thereafter the rest of the afternoon was cloudy, the sunshine total for the day being 2.9 hours. After a night minimum temperature of 1.7°C the temperature at the time was 4.7°C, later rising to a maximum of 7.0°C, just 0.2°C below the 30 Year (1973/2002) average for this day. The previous day had been the wettest day of the month so far, albeit with a relatively modest 4.9 millimetres rainfall in a dry month to date (only 8.2 millimetres rainfall from 1st to 17th). A feature of the morning on 27th December 2004 was the exceptional brightness for a winter's day despite thin high cloud and a multitude of aircraft contrails turning the sunshine rather hazy at times. In this picture at 1200 GMT the construction site of the A505 Baldock by-pass (13 km SW of Royston) is viewed from the Wallington Road looking southwards towards the Weston Hills (on the horizon) which the road will navigate through a cutting and tunnel before reaching the existing roundabout at Letchworth Gate. The chalk embankment seen on the right here has already been largely covered with top soil concealing at this point the overriding chalk white impression of the whole length of the site. 

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(This page last updated 8th January 2005 2043 GMT)