PITSFORD HALL WEATHER STATION NORTHAMPTON, UNITED KINGDOM MONTHLY WEATHER REPORT - JULY 2004 Headline: Changeable at first but becoming more settled and warmer. The first few days of July saw a depression tracking to the north of the county bringing a spell of unsettled weather marked by sunny spells and occasional showers. The 2nd saw particularly heavy and thundery showers with 3.9mm falling in a little under an hour. A second low tracked to the south of the county on the 4th maintaining the unsettled conditions. The 5th and 6th were particularly fine days across the county thanks to high pressure extending in from the west. Both days saw more than 10 hours of sunshine. However, from the 7th onwards a deep depression worked up from the continent bringing a spell of wet and windy weather more typical of autumn. 29.1mm fell over 10hours at Pitsford on the 7th and winds gusted to 42mph. With a mainly north or north-westerly airflow temperatures remained fairly depressed. From the 12th anticyclonic conditions developed across the south of the UK and winds swung round to a warmer south or south-westerly direction. It became rather cloudy at times and a fairly stationary frontal wave gave rise to spells of rain on the 13th and 15th. Some nights became rather close as temperatures on the 16th and 17th held up at around 15.8C. High pressure remained in place until the 19th following which fairly slack conditions prevailed across much of the UK. Winds were very light or calm at times. Although some good spells of sunshine were recorded (12.8 hours on the 23rd), there were occasional showers sometimes thundery. During the last week, high pressure built up again across much of the UK. As it drifted eastwards some warm and humid air was drawn in from the continent. Daytime temperatures climbed to the mid to high 20s peaking at 28.2C on the 29th. Whilst weak frontal systems moved in to affect mainly the northern half of the UK, with the exception of some very light showers on 29th, the month of July ended on a warm and dry note across the county. Air Temperatures The Highest Maximum: 28.2C on 29th The Lowest Maximum: 17.7C on 12th The Highest Minimum: 15.8C on 16th The Lowest Minimum: 7.3C on 10th The Mean Maximum: 21.8C The Mean Minimum: 11.4C The Overall Mean: 16.6C Difference from the Monthly Mean: -0.7C Relative Humidity: Highest Relative Humidity (at obs): 96.9% on 14th Lowest Relative Humidity (at obs): 61.6% on 28th Mean Relative Humidity (at obs): 77.6% Dew Point: The Highest Dew Point (at obs): 16.9C on 16th The Lowest Dew Point (at obs): 9.8C on 9th The Mean Dew Point (at obs): 13.0C Rainfall: Total: 49.0mm Difference from the Monthly Mean: 102.3% Duration: 24.8hrs Highest 24 hour fall (obs to obs): 29.1mm on 7th Rain Days (>/=0.2mm): 15 Wet Days (>/=1.0mm): 11 Sunshine: Total Duration of Bright Sunshine: 156.1hrs Sunniest day: 12.8hrs on 23rd Days without sunshine: 1 Cloud cover (mean at obs): 6.0oktas Pressure (reduced to sea level): The Highest Pressure: 1025.8mb on 24th The Lowest Pressure: 1005.2mb on 8th Mean Pressure (recorded at obs): 1015.3mb Winds Run of wind (mean over 24 hrs): 92.2miles Mean daily wind speed: 5.0mph Highest mean daily wind speed: 12.2mph on 7th Run of wind (to date): 2858.1miles Highest Maximum Gust: 42mph on 7th Highest wind strength (at obs): 16.1mph on 7th Mean wind strength (at obs): 5.3mph Winds from the Following Directions: N 2 NE 2 E 0 SE 3 S 5 SW 2 W 3 NW 13 Calm 1 Ground Temperatures: Lowest Grass Minimum: 4.1C on 13th Mean Grass Minimum: 9.0C Lowest Concrete Minimum: 6.8C on 13th Mean Concrete Minimum: 11.1C Lowest Bare Earth Minimum: 6.9C on 13th Mean Bare Earth Minimum: 11.8C Soil/Earth Temperatures: Surface mean: 17.9C 5cm mean: 16.5C 10cm mean: 16.9C 20cm mean: 17.1C 30cm mean: 17.4C 40cm mean: 17.3C 50cm mean: 17.5C 100cm mean: 15.9C Days with: Thunder: 2 (2nd & 22nd) 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) 87.58mm