Andrew Roberts with more useful information from the Extending your season feature in Yachting World's Practical Cruising series in September 2006 issue.
September: the start of severe weather?
According to sailor’s lore, the time around the autumnal equinox on 23 September is a period of strong winds and gales. In reality, there is not much evidence of a pattern of equinoctial gales and statistics from the UK Met Office illustrate that they are no more likely to occur then that at any other time in September. On a 30-year average between 1961 and 1990, Plymouth had less than one day of gales in September but there is a steady rise through the late autumn. In other words, you could still rely on most days to provide good, easy sailing.
As you get further north September is less kind. On the west coast of Scotland, there were on average nearly three times as many gales as in Plymouth the same month. If wind strengths are the deciding factor on how long you continue sailing, the answer is to move your boat further south later in the season.
On other measures late autumn can be very pleasant. The water temperature is warmer than in spring. In the West Country it is still 18°C in September. Fog is much less common than in the summer months as the statistics say that there is only a 2% chance of fog in the English Channel in September compared to 3% in June. However, the declining strength of the sun means that any fog that does form stays longer and easterlies bring a greater risk of fog to the east coast.
Other good news is that air temperatures stay high. The hottest day of the year often falls in September and temperatures as high as 34°C have been recorded. However, extreme weather is not unknown. The tail end of a hurricane can fuel storms, or they can arise locally in thunderstorms. The ‘Great Storm’ of 1987, when two lows collided, developed a central pressure of 958mb and wreaked havoc, while Britain’s worst hailstorm hit Sussex 50 years ago, firing out balls of hail that were found to measure 70mm across.
All quiet on the western front
Crowds on the most popular stretches of the coast thin out as soon as the schools go back, returning the visitors’ berths and anchorages to peace and quiet. In Salcombe, for example, which is packed in August, the last Bank Holiday is a turning point and visitors by yacht drop from 100 a day to 25 a day. In October, they are ‘a trickle,’ says the Salcombe harbour office.
The same exodus is seen in Dartmouth and Weymouth. Visiting boats after August are usually from another local port. Facilities and restaurants are still in full swing, however, and water taxis run all year round although on shorter hours in winter.
Visitor numbers do decline closer to the Solent as well, but not to the same extent because the ports are more accessible. Surprisingly Guernsey visitor numbers do not fall off very significantly because patterns are changing. Graham Trebeit, a duty Harbour Officer in Guernsey for over 20 years says, whilst patterns are changing, the season is getting longer and we don’t have peaks in August in the way we used to, the autumn is still a very pleasant time to be here.
Autumn gear – big and small
Hot air heater, eg Eberspacher or Webasto. Rapidly takes effect. Keeps the boat dry and sweet. Unobtrusive. Low diesel consumption of about 0.25 litres per hour. Make sure the exhaust side of the installation will work offshore. Typical cost: £1,000-£2,000.
Cockpit cover or tonneau cover. Many builders offer them as extras to zip on to the back of a sprayhood. Great for keeping driving rain out of the hatch, and a ‘conservatory’ for wet oilskins, boots etc.
Digital barometer. The easiest way to keep track of how pressure is trending, and be forewarned of weather deteriorating faster than was forecast.
Thermals. They make a huge difference in cold weather. The latest are light and breathable and have an antimicrobial finish.
TV. Raymarine’s satellite TV dome interfaces with their E series display and is latest thing with the motorboat crowd, so can it be long before they are commonplace on yachts?
Hot water bottle. Failsafe technology from the other end of the scale. As voted for by ybw.com forum users.
The full ‘Extending your season’ feature appeared in the September 2006 issue. To subscribe click here