PITSFORD HALL WEATHER STATION NORTHAMPTON, UNITED KINGDOM MONTHLY WEATHER REPORT - SEPTEMBER 2004 Headline: Fine and settled during the first week, but then turning unsettled with frequent blustery showers and outbreaks of rain. Generally warm throughout. September began on a fine and settled note. The first week saw some decent sunny spells with respectable temperatures. Daytime maxima were generally in the mid 20s with a high of 26.4C on the 5th. Many parts turned rather dull and cloudy on the 6th including the county with some patchy light rain or drizzle. However, the following few days saw a return to drier and brighter weather although the mornings saw some fairly extensive mist and patchy fog. The weather became more unsettled from the 10th onwards. In fact some notable rainfall amounts were noted especially on the 12th which saw 8.1mm recorded in just under 5 hours. Despite the cloud and rain most days had some respectable sunshine totals. It also became fairly windy with peak gusts exceeding 30mph every day between the 11th and 14th. The county enjoyed a brief respite on the 15th. Clear skies overnight saw temperatures fall quite sharply to 4.7C on the morning of the 16th with a ground frost narrowly being avoided as grass minima at Pitsford fell to 1.9C. However, further showers and longer spells of rain pushed their way through the county from the 16th onwards and it stayed generally unsettled right through to the end of the month. Fortunately, the worst of the wet weather was experienced further west and the county enjoyed being in the rain shadow as fronts delivered much of their load to parts of Wales and the west. Despite the wet weather it remained fairly mild with daytime maxima reaching the mid to high teens. It turned rather windy once again from the 19th through to the 23rd. Air Temperatures The Highest Maximum: 26.4C on 5th The Lowest Maximum: 14.4C on 24th The Highest Minimum: 14.7C on 18th The Lowest Minimum: 4.7C on 16th The Mean Maximum: 19.5C The Mean Minimum: 10.8C The Overall Mean: 15.2C Difference from the Monthly Mean: 1.2C Relative Humidity: Highest Relative Humidity (at obs): 98.9% on 30th Lowest Relative Humidity (at obs): 67.7% on 1st Mean Relative Humidity (at obs): 82.3% Dew Point: The Highest Dew Point (at obs): 16.6C on 5th The Lowest Dew Point (at obs): 5.6C on 24th The Mean Dew Point (at obs): 12.2C Rainfall: Total: 41.1mm Difference from the Monthly Mean: 72.4% Duration: 43.0hrs Highest 24 hour fall (obs to obs): 8.1mm on 12th Rain Days (>/=0.2mm): 14 Wet Days (>/=1.0mm): 10 Sunshine: Total Duration of Bright Sunshine: 156.2hrs Sunniest day: 10.3hrs on 2nd Days without sunshine: 3 Cloud cover (mean at obs): 5.0oktas (62.5%) Pressure (reduced to sea level): The Highest Pressure: 1035.5mb on 8th The Lowest Pressure: 995.9mb on 14th Mean Pressure (recorded at obs): 1018.0mb Winds Run of wind (mean over 24 hrs): 127.0miles Mean daily wind speed: 6.9mph Highest daily wind speed: 12.7mph on 12th Run of wind (to date): 3809.4miles Highest Maximum Gust: 37mph on 20th Highest wind strength (at obs): 24.2mph on 14th Mean wind strength (at obs): 8.1mph Winds from the Following Directions: N 1 NE 2 E 3 SE 2 S 6 SW 4 W 5 NW 5 Calm 2 Ground Temperatures: Lowest Grass Minimum: 0.6C on 25th Mean Grass Minimum: 7.8C Lowest Concrete Minimum: 4.1C on 25th Mean Concrete Minimum: 9.4C Lowest Bare Earth Minimum: 5.4C on 24th Mean Bare Earth Minimum: 10.4C Soil/Earth Temperatures: Surface mean: 14.7C 5cm mean: 14.3C 10cm mean: 14.7C 20cm mean: 15.3C 30cm mean: 15.9C 40cm mean: 15.8C 50cm mean: 16.3C 100cm mean: 15.9C Days with: Thunder: 0 Hail less than 0.5mm: 0 Hail greater than/equal to 0.5mm: 0 Snow or snow & rain: 0 Fog 0 Ground frost: 0 Air frost: 0 Total Evaporation (tank) 66.19mm