PITSFORD HALL WEATHER STATION Northampton, United Kingdom MONTHLY WEATHER REPORT - June 2005 Headline: A fairly typical June with very warm spells ending in a thundery breakdown and heavy showers, especially in the final week. A very hot spell around mid-month saw the warmest June day since 1976. A rather unsettled start to the month. Frontal systems worked eastwards through the county producing a couple of particularly wet days on the 1st and 3rd and showers throughout the period until the 6th. Apart from the 4th sunshine totals were rather modest for the start of June with daytime maxima in the mid to high teens. High pressure began to build from the 7th onwards bringing a spell of fine weather across the county. Daytime temperatures climbed to the low 20s, although some clear nights saw air minima fall fairly smartly to 3.1C on the 7th which also saw the only ground frost of June. There was some good sunshine. 11.9 hrs were recorded on both the 7th and the 8th and winds remained generally light. The high began to retreat westwards from the 10th and with a cool northerly airstream temperatures consequently tumbled. Low pressure, centred over the North Sea on the 14th, introduced the second spell of unsettled weather. There was a fair amount of cloud and rain, although a switch to a south or south-easterly airstream kept it fairly mild by day and the cloud ensured that temperatures overnight remained in double figures. Anticyclonic conditions returned on the 17th and the maintenance of the south-easterly breeze off the near continent gave rise to a very warm spell with temperatures rapidly climbing to 31.0C on the 19th, the warmest June day since the summer of 1976. The high then slipped away eastwards and as it did so thundery downpours were experienced across parts of Wales and northern England. However, the county escaped unscathed and continued to enjoy the warm weather as it held on in the south-east. The Azores high pressure built in again from the 21st and temperatures once again climbed to a high of 29.2C on the 23rd. There was some good sunshine, 12.8 hrs on the 22nd and 13.0hrs on the 23rd. However, pressure fell on the 24th and on this occasion the county caught the full force of the thundery downpours with 22.3mm of rain recorded in just under 3 hrs at Pitsford Hall. The switch from a south-westerly to a north or north-easterly airstream saw temperatures fall away quite smartly over the next couple of days. As the month drew to a close a transient ridge of high pressure on the 26th and 27th gave way quite quickly to low pressure and some particularly unsettled weather. A warm day on the 28th broke down during the early evening giving rise to some spectacular thunderstorms tied into a front moving up from the south-west. 11.2mm fell in just under 3 hrs at Pitsford Hall. A particularty humid day on the 29th also saw further thunderstorms with light showers continuing on the 30th. Air Temperatures The Highest Maximum: 31.0C on 19th The Lowest Maximum: 14.4C on 11th The Highest Minimum: 17.2C on 20th The Lowest Minimum: 3.1C on 7th The Mean Maximum: 21.0C The Mean Minimum: 10.9C The Overall Mean: 16.0C Difference from the Monthly Mean: +1.0C Relative Humidity: Highest Relative Humidity (at obs): 95.9% on 25th Lowest Relative Humidity (at obs): 58.8% on 23rd Mean Relative Humidity (at obs): 76.5% Dew Point: The Highest Dew Point (at obs): 20.0C on 18th The Lowest Dew Point (at obs): 5.9C on 7th The Mean Dew Point (at obs): 12.6C Rainfall: Total: 57.5mm Difference from the Monthly Mean: 100.7% Duration: 21.3hrs Highest 24 hour fall (obs to obs): 22.3mm on 24th Rain Days (>/=0.2mm): 10 Wet Days (>/=1.0mm): 8 Sunshine: Total Duration of Bright Sunshine: 181.9hrs Sunniest day: 13.0hrs on 23rd & 27th Days without sunshine: 2 Cloud cover (mean at obs): 5.6oktas (70%) Pressure (reduced to sea level): The Highest Pressure: 1037.6mb on 8th The Lowest Pressure: 1005.2mb on 30th Mean Pressure (recorded at obs): 1018.8mb Winds Run of wind (mean over 24 hrs): 86.9miles Mean daily wind speed: 4.7mph Highest mean daily wind speed: 7.7mph on 15th Run of wind (to date): 2605.5miles Highest Maximum Gust: 29mph on 4th Highest wind strength (at obs): 12.7mph on 4th Mean wind strength (at obs): 6.0mph Winds from the Following Directions: N 7 NE 2 E 1 SE 5 S 5 SW 2 W 5 NW 3 Calm 0 Ground Temperatures: Lowest Grass Minimum: -0.4C on 7th Mean Grass Minimum: 7.8C Lowest Concrete Minimum: 3.5C on 7th Mean Concrete Minimum: 11.3C Lowest Bare Earth Minimum: 4.1C on 7th Mean Bare Earth Minimum: 11.0C Soil/Earth Temperatures: Surface mean: 18.3C 5cm mean: 16.2C 10cm mean: 16.4C 20cm mean: 16.4C 30cm mean: 16.6C 40cm mean: 16.4C 50cm mean: 16.4C 100cm mean: 14.3C Days with: Thunder: 3 Hail less than 0.5mm: 0 Hail greater than/equal to 0.5mm: 0 Snow or snow & rain: 0 Fog 1 Air Frost: 0 Ground Frost: 1 Gales: 0 Total Evaporation (tank) 89.16mm All data © Pitsford Hall weather station.