Solar maximum is coming, but we won't know it happened until 7 months after it's over

Solar maximum could occur as early as mid-2024 but scientists will have to wait seven months after it has occurred to be able to declare it has taken place. Why?

Solar maximum is coming, but we won't know it happened until 7 months after it's over
Solar maximum could occur as early as mid-2024 but scientists will have to wait seven months after it has occurred to be able to declare it has taken place. Why?