Heat and cold have a significant impact on your ball's performance. When it's cold, balls will take longer to warm up and won't bounce as high, no matter the type of ball. Don't be surprised - just use a blue or red ball when it's very cold. On the other hand, the warmer it is, the more your ball will bounce. Counter this effect by using a ball that doesn't bounce as high, such as a yellow dot or double yellow dot.