Diego Garcia Island • Statistics for January

January: The Winter Window - Westerly Winds and Manageable Swell

January opens the year with Diego Garcia's most balanced surf conditions. The average swell height is around 5ft (1.6m) with a long-period 10.8s groundswell, and the ideal offshore wind statistic reaches 42 percent. The wind rose shows a strong WSW-W-WNW signal, with W and WNW combined pushing close to 43 percent of all observations and a good chunk of that at 20-30kph. These are exactly the offshore directions that groom the east-facing reefs. Swell direction is still dominated by the south: S (25.7%), SSE (23.3%) and SSW (19.7%) make up the bulk of the energy, so you are not getting true west-northwest groundswell very often. However, WSW (5.9%) and W (3.1%) contributions are at their annual peak, and with warm 28.7°C water and a humid 27.4°C airmass, a decent westerly swell underneath favourable winds can produce surprisingly good surf. The main challenge is precipitation: January is one of the wettest months, with 8.76mm/day, so plan for rain showers between sets.