Monday 21st September
The variable sunshine on Sunday morning very slowly lifted the temperature but it wasn’t until around midday that the sun began to shine more strongly that resulted in a maximum of 19.7C at 15.48, being 0.7C above average. By the late afternoon the sun was very strong, thanks to clear air and skies from the northwesterly light breeze that also limited the rise in temperature.
The past night was very cool due to clear skies and the lingering cool air from the northwest that produced a minimum of 5.4C, which was logged at 06.27 on Monday, just before sunrise in Marlborough at 06.51. The lack of air movement also contributed to the low temperature as the breeze dropped out just after 21.00, with a light whisper just before midnight, and the anemometer stationary since then and up to this morning. Due to the much later sunrise at this time of year there was little rise in temperature initially that meant by 08.00 the thermometer had only reached 6.8C, which was the coldest night since 16th May (3.3C) and the coolest start to a new day at that time since 15th May.
Monday got off to a good start with the sun shining as it rose above the horizon through very thin, high cloud. We have a splendid day ahead although variable cloud might spill in from the northwest mid-morning, there is a divergence of opinion between the two main forecasters, however, with much sunshine the temperature will rise several degrees above the late September average.
The centre of the anticyclone is almost overhead with a very high barometric pressure reading of 1032.9mb at 08.00, which is the highest pressure reading since last December. The high pressure will mean warm, sunny days with variable cloud and calm conditions this week before the wind veers into a more northerly direction on Thursday that will see the temperature drop a degree or two, but still above average.
The high pressure will stay with us until probably Friday when it will slide away eastwards whilst a deep depression edges in from the northwest that will attempt to usher in a weather front across the country behind the departing anticyclone, when maximum temperatures will likely return to around average.
