Understanding the availability of wind turbines(WT) is vital to maximise WT energy production and minimise the payback period. Previous work tended to concentrate on the location of unreliability or failure modes in a WT. This paper investigates the influence of weather and location on WT failure rate and downtime, to understand the root causes and consequences of failure. The paper furthers a previous study covering the whole of Denmark by considering a limited population of identical WTs, located at 3 disparate German sites, using data extracted from the WMEP programme and local weather data, thereby focusing more precisely than previously. The WMEP and associated weather data were analysed to find the WT failures and weather conditions and then cross-correlate them. The reliability characteristics of the WT populations followed the average t rends of the WMEP survey. Annual periodicity was found in the weather data but not in individual WT population failures. However, a strong crosscorrelation can be seen between failures and weather data. This cross-correlation appears
stronger than found in the earlier, larger study, vindicating our more focused approach. It is clear that Operation and Maintenance has an impact on WT downtime and will be more important offshore. This work may indicate how weather may affect the availability of offshore WTs.