Q.Why is my Helebore flowering in August?
I have several Hellebores, but one burst into flower early. In August! It’s now late September , and it’s still in flower. Is this unusual? (My other 4 Hellebores are not flowering). Will it flower again in winter?

One reason people love to garden is that you never know for sure what will happen. Plants are individuals, and don't read rule books. Sometimes one may do something odd just because it wants too. One possibility for early blooming is that they are young plants - they can take 3 or 4 years to mature. Youngsters often do things that older, more experienced types will not do. Perhaps the weather was cool and rainy, and your plant was tricked into thinking it was time to flower. Here is more information on hellebores: https://www.gardeningknowhow.com/ornamental/flowers/hellebore/growing-hellebores.htm