WEATHER REVIEW - January 2009
Headline: Anticyclonic and very cold for much of the first half of the
month, becoming increasingly unsettled with frequent frontal systems bringing
rain working through during the second half.
The weather for the first week and a half
of January was dominated by essentially anticyclonic conditions. High pressure initially
placed with its centre to the north of
The cold weather finally released its grip
on the county on the 11th with winds swinging round to a milder south-westerly
direction. Active frontal systems piled into northern and western
A ridge of high pressure developed across
the
From the 15th onwards the county
experienced quite a disturbed spell of weather.
Frontal systems linked to some deep lows worked eastwards across the
region in quick succession bringing frequent outbreaks of rain and some strong
winds, the strongest gusts reaching 49mph at Pitsford on the 17th. Barometric
pressure associated with this particular low dropped to 946mb at its centre
north of
As the month came to a close, high
pressure took up residence over
Thanks to the cold snap at the beginning
of the month, this month was the coldest January in
Air Temperatures
The Highest Maximum: 9.6 C on 22nd
The Lowest Maximum: 1.2 C on 4th
The Highest Minimum: 5.4 C on 17th
The Lowest Minimum: -5.5 C on 6th
The Mean Maximum: 5.8 C
The Mean Minimum: 0.1 C
The Overall Mean: 3.0 C
Difference from the Monthly Mean: -0.8 C
Black Bulb
Maximum (at 0900): 8.3 C on 22nd
Mean (at 0900): 2.3 C
Relative Humidity:
Highest Relative Humidity (at 0900): 100.0 % on 10th, 14th, 19th, 27th
Lowest Relative Humidity (at 0900): 74.3 % on 17th
Mean Relative Humidity (at 0900): 94.0 %
Dew Point:
The Highest Dew Point (0900): 8.3 C on 22nd
The Lowest Dew Point (at 0900): -6.0 C on 6th
The Mean Dew Point (at 0900): 1.5 C
Rainfall:
Total: 35.9 mm
Percentage of the Monthly Mean: 68.6 %
Duration: 35.2 hrs
Highest 24 hour fall (0900 to 0900): 5.7 mm on 27th
Rain Days (>/=0.2mm): 14
Wet Days (>/=1.0mm): 11
Sunshine:
Total Duration of Bright Sunshine: 41.0 hrs
Sunniest day: 6.2 hrs on 18th
No. of days without sunshine: 12
Percentage of the Monthly Mean: 92.3 %
Cloud cover (mean at 0900): 6.5 oktas (81.3 %)
Pressure (reduced to sea level):
The Highest Pressure (at 0900): 1031.8 mb on 1st & 2nd
The Lowest Pressure (at 0900): 972.3 mb on 23rd
Mean Pressure (at 0900): 1010.4 mb
Winds
Run of wind (mean over 24 hrs): 154.2 miles
Mean daily wind speed: 8.4 mph
Run of wind (cumulative): 4781.3 miles
Highest Maximum Gust: 49 mph on 17th
No. of gusts of 50mph or more: 0
Highest wind strength (at 0900): 25.4 mph on 11th
Mean wind strength (at 0900): 8.0 mph
Winds from the Following Directions:
N 2 NE 2 E 1 SE 4 S 11 SW 5 W 2 NW 2 Calm 2
Concrete
Lowest Concrete Minimum: -8.0 C on 8th
Mean Concrete Minimum: -2.2 C
Evaporation
Piche 32.3 ml
Pan Not available
Days with:
Thunder: 0
Hail <5mm: 0
Hail >/=5mm: 0
Snow or snow & rain: 3
Snow lying: 3
Fog: 3
Air Frost: 15
Duration of Air Frost: 102 hrs
Gales: 0
All data © Pitsford Hall weather station.
Click here to view the weather diary for January 2009.
Click here to view the full AWS weather record for January 2009.
Click here to view the statistical summary for 2009.
The weather station publishes a full Monthly Weather Report (ISSN 1741-4733) which is distributed to libraries across Northamptonshire. This report comprises a full UK weather diary, reports of extreme weather events across the county, statistics from Pitsford Hall's affiliated stations across the county as well as news from the weather station itself. Individuals may download this report for £2 or take out an annual subscription for the paper-based report for £25. Click here for further details.