A mild (+0.8°C), sunny (129.1%) month with rainfall
(100.4%) very close to normal.
Low pressure over southern Scandinavia
gave a cold start to the month with strong west to northwesterly winds and
wintry showers. On the 3rd
a deep low tracked east across the Borders, bringing strong to gale force
northeasterly winds and further wintry showers to the north.
Low pressure remained anchored over
Denmark until the 9th when a ridge of high pressure, building
southwest across northern Britain from Scandinavia, resulted in a brief settled
spell with fresh southeast to southerly winds.
From the 11th a large area of
low pressure became established to the south of Iceland, bringing a very
unsettled spell with rain and strong to gale force southerly winds as associated
fronts moved east across the British Isles.
A vigorous Atlantic low, tracking
northeast on the 14th, passed closed to Faeroe early on the 15th
- with heavy rain and strong to gale force south to southwesterly winds.
Further lows, tracking northeast close to Iceland, maintained the mild
and showery southwest to westerly airflow until the 18th when the
main center of low pressure moved into the Norwegian Sea and the strong to gale
force winds veered northwesterly – bringing colder conditions and a return of
the wintry showers.
The cold northerly airflow was
maintained across Shetland - modified on several occasions as small lows tracked
quickly east across northern Scotland - until the 25th, when a
complex area of low pressure, developing across the northern North Sea, finally
disrupted the flow.
The 28th saw a ridge of high pressure build and quickly decline, with a large area of low pressure subsequently developing over southeast Iceland and the Norwegian Sea – with mild southwesterly winds across western and northern Scotland. The month ended fine, dry and sunny as a ridge of high pressure built across Shetland.
 | Daily Data |
| Weather Diary |
|
1999 |
Day |
1974-98 |
1999 |
Day |
1974-98 |
|||
|
Mean Maximum Temperature |
6.9 |
6.1 |
Highest Max temp |
9.6 |
29 |
10.9 |
||
|
Mean Minimum Temperature |
4.0 |
3.2 |
Lowest Min temp |
0.6 |
22 |
-5.0 |
||
|
Mean Sea Temperature |
7.7 |
7.0 |
Lowest grass minimum |
-3.0 |
2 |
-12.5 |
||
|
30 cm Earth temperature |
4.9 |
4.7 |
Days with ground frost |
2 |
9.5 |
|||
|
100cm Earth temperature |
5.1 |
5.1 |
Days with air frost |
0 |
3.2 |
|||
|
Total Rainfall (mm) |
84.9 |
84.6 |
Days with snow/sleet |
8 |
12.2 |
|||
|
Wettest Day (mm) |
15.7 |
2 |
14.0 |
Days with snow cover at 09hr |
0 |
2.7 |
||
|
Rain Days (> 0.1mm) |
23 |
23.0 |
Days with hail |
6 |
11.5 |
|||
|
Wet Days (> 0.9mm) |
13 |
17.0 |
Days with fog during 24hrs |
4 |
4.0 |
|||
|
Total sunshine, hrs |
122.6 |
96.2 |
Days with fog at 09hrs |
1 |
0.8 |
|||
|
Sunniest day, hrs |
9.9 |
27 |
9.3 |
Days with NIL sun |
7 |
7.5 |
||
|
Mean wind speed, kts |
17.1 |
18.9 |
Days with gale |
3 |
7.7 |
|||
|
Maximum gust, kts |
75 |
3 |
66.7 |
Days with thunder |
0 |
0.5 |
||
|
Mean Sea Level pressure |
1003.6 |
1007.5 |
Days with aurora |
3 |
4.0 |
|||
|
Wind Direction (%) North |
12.9 |
9.4 |
Wind Direction (%) S. West |
6.5 |
16.7 |
|||
|
at 09 hr N. East |
0.0 |
4.0 |
at 09 hr West |
22.6 |
17.3 |
|||
|
East |
3.2 |
7.9 |
N. West |
6.5 |
9.4 |
|||
|
S. East |
3.2 |
13.8 |
||||||
|
South |
45.2 |
20.4 |
CALM |
0.0 |
0.9 |
