Weather Forecasts
The Beaufort Wind Scale
Description | Force | Speed (Knots) | Sea |
Light Airs | 1 | 1-3 | Ripples |
Light Breeze | 2 | 4-6 | Small Wavelets |
Gentle Breeze | 3 | 7-10 | Occasional Crests |
Moderate | 4 | 11-16 | Frequent White Horses |
Fresh Breeze | 5 | 17-21 | Moderate Waves, Many White Crests |
Strong Breeze | 6 | 22-27 | Large Waves, White Foam Crests |
Near Gale | 7 | 28-33 | Sea heaps up, spray, breaking waves, foam blows in streaks |
Gale | 8 | 34-40 | Moderately high waves, breaking crests |
Severe Gale | 9 | 41-47 | High waves, spray affects visibility |
Storm | 10 | 48-55 | Very high waves, long breaking crests |
Violent Storm | 11 | 56-63 | Exceptionally high seas with continuously breaking waves affecting visibility |
Hurricane | 12 | 64 and above | Exceptionally high seas, with continously breaking waves seriously affecting visibility |
The weather is a key element to the operation of a boat. This page details some useful information about the weather you can expect during the year. The figures given below are from a variety of sources.
Air Temperature
Probably the measure that most directly influences us. Below is the average temperatures that we can expect, as well as typical high and low values that are likely to be experienced.
C | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Avg | 5 | 5 | 7 | 8 | 12 | 15 | 17 | 17 | 15 | 12 | 8 | 6 |
Low | 2 | 3 | 4 | 5 | 8 | 11 | 14 | 13 | 11 | 9 | 5 | 3 |
High | 7 | 7 | 10 | 12 | 16 | 18 | 21 | 20 | 18 | 15 | 11 | 8 |
Sea Temperature
For diving the key to the comfort during the dive is the sea temperature. June – October are the months of the warmest water, but often the warm water brings the algae that spoils the visibility. The dive season often starts at Easter. This is when the water is just starting to warm but the water is clear.
C | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Sea | 9 | 8 | 8 | 9 | 11 | 14 | 16 | 17 | 17 | 15 | 13 | 11 |
Sun
The hours of sunshine on a daily during the day is not surprisingly May-Jul when the days are the longest.
Hrs | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Sunshine | 4 | 5 | 6 | 9 | 10 | 11 | 10 | 8 | 8 | 6 | 4 | 4 |
Wind Speed
The wind is the crucial aspect of the weather for the comfort at sea. The average wind speed is consistent over the year. However, this does not reflect the gales and doldrums we experience in the English Channel
Kts | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Wind | 11 | 10 | 10 | 10 | 10 | 9 | 10 | 9 | 10 | 10 | 10 | 10 |
Rainfall
Rainfall is the opposite to the sun in contributing how we feel about the days weather. Listed below is the average rainfall in mm we can expect each month.
mm | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Rain | 79 | 65 | 46 | 51 | 37 | 55 | 45 | 37 | 51 | 78 | 64 | 70 |
Humidity
Not surprisingly the Relative Humidity is fairly constant thanks to the sea.
% | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
RH | 87 | 84 | 81 | 79 | 79 | 80 | 80 | 78 | 80 | 82 | 85 | 87 |