About this page
Some sources of planning data are identified. No doubt, there are many more.
A good start for any planning of cruising is, of course, the Admiralty Sailing directions (which are available on CD) and contain some limited weather information. These were the basis of pages on this site referring to the Baltic, Western Mediterranean and Trans-Atlantic weather.
UK Land Climatological Data
Land climate data have been collected for several hundreds of years but National Meteorological Services, such as the UK Met Office, usually compile these over 30 year periods. This ensures that the latest averages are likely to be relevant for planning and design purposes. Care is taken to minimise the effects of local environmental changes and developments in instrumental techniques and observational methods. For the UK, a starting point is the Met Office Climate and the Climate and Statistics pages. A quick link to individual long term, station statistics is at the Historic Station data page. A bigger list of stations is at the Climate Averages page where there are 1961-1991 and 1971-2000 averages.
Marine Climatological Data
( Losses of ships, at a time when world trade was increasing, led to Governments waking up to the idea that international co-operation in meteorology might pay useful dividends. The first International Meteorological Conference was held in Paris in 1853. The leading light, Lieutenant Maury, a beached US Navy Officer, proposed standard times, methods of observing and logging format for weather reports from ships at sea.
The observations were to be made available to national marine authorities and exchanged freely between nations. This process continues today with some 7000 merchant ships voluntarily observing the weather. Nowadays, most ships report in real time as well as returning weather logs (increasingly as computer files) to their national weather services.
A Deutscher Wetterdienst page gives a brief summary of the Global Data Collection Scheme. The Met Office marine archive now has getting on for 100 million observation from ships world- wide dating back mainly to the mid 1850s with a few (eg HMS Beagle) from earlier times. This archive is an invaluable tool for such purposes as risk analysis, climate definition and climate change studies.
The US Navy Fleet Numerical and Oceanography Detachment based at the US National Data Collection Center, Asheville, NC, has made available much of these marine data online. The main index for their Marine Data Archive is available online with a useful, if somewhat frightening Weather Extremes page. Another link for global wave data is available from the Dutch weather service, KNMI.
For pointing me at some of these links, I would like to thank Martin Rowley who has a very useful general weather information site and Sarah North Marine Networks Manager at the Met Office, Exeter.