The economic success of farming is subject to fluctuations due to volatile costs, yields and prices. To reduce performance risk, weather index insurances (WII) can be used. These instruments usually address a single risk factor. Its capacity to reduce farm specific performance risk, however, must be evaluated by measuring how WII reduce the volatility of a relevant performance figure. The aim of this study is to analyze how WII reduce the volatility of farm specific total gross margins. Measure is the hedging efficiency (HE), which is determined by a historic simulation and a risk programming approach. For most analyzed farms the HE was quite low or performance risk increased using WII. The whole-farm HE varies depending on the hedging strategy and is highly farm specific. Due to the influence of other risk factors, it is necessary to analyze the HE of WII with regard to a relevant superordinate performance figure. This is important to derive well-grounded risk management decisions.