San Juan Seasonal Surf Averages

Based on the last ten years data for this location this page gives seasonal trends and an idea of what kind of conditions you can expect and when. Of course these are just averages - it's worth reading carefully to understand exactly what they mean and to recognise the kind of variation you could expect on a trip because an average can never tell the whole story. Click on a month below to see more detail. If you want a past forecast for a specific date range then click here.

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Swell Consistency and Wind Overview

90% 79% 11% Jan

81% 58% 23% Feb

88% 67% 21% Mar

78% 45% 33% Apr

68% 22% 46% May

44% 6% 38% Jun

37% 1% 36% Jul

42% 6% 36% Aug

58% 29% 29% Sep

83% 57% 26% Oct

80% 57% 23% Nov

88% 70% 18% Dec

Monthly Overview

Jan Swell Consistency 90% Average Swell Height 8ft Average Swell Period 12s Dominant Wind Dominant Swell	Feb Swell Consistency 81% Average Swell Height 7ft Average Swell Period 11s Dominant Wind Dominant Swell	Mar Swell Consistency 88% Average Swell Height 7ft Average Swell Period 11s Dominant Wind Dominant Swell	Apr Swell Consistency 78% Average Swell Height 7ft Average Swell Period 10s Dominant Wind Dominant Swell
May Swell Consistency 68% Average Swell Height 6ft Average Swell Period 9s Dominant Wind Dominant Swell	Jun Swell Consistency 44% Average Swell Height 5ft Average Swell Period 9s Dominant Wind Dominant Swell	Jul Swell Consistency 37% Average Swell Height 6ft Average Swell Period 8s Dominant Wind Dominant Swell	Aug Swell Consistency 42% Average Swell Height 5ft Average Swell Period 8s Dominant Wind Dominant Swell
Sep Swell Consistency 58% Average Swell Height 5ft Average Swell Period 10s Dominant Wind Dominant Swell	Oct Swell Consistency 83% Average Swell Height 6ft Average Swell Period 11s Dominant Wind Dominant Swell	Nov Swell Consistency 80% Average Swell Height 8ft Average Swell Period 11s Dominant Wind Dominant Swell	Dec Swell Consistency 88% Average Swell Height 8ft Average Swell Period 12s Dominant Wind Dominant Swell

Understanding this Data

These swell averages are calculated ONLY on swells of more than 7 seconds period. This means this is the average height of a swell that's likely to produce ridable surf NOT an average of every wave heading toward the beach in a month. Likewise the period is the average period OVER 7 seconds. There will be days that have short period wind swells that won't produce and ridable swell and these are excluded from the averages. The consistency figure gives the percentage of days that meet this condition.

For example if the consistency is 50% you could expect the 'average' swell for about 15 days in the month. Of course an average tells only part of the story. A combination of very large and very small swells may produce the same average as a consistent medium sized swell.