What is a word that could describe something that would be inconvenient under normal cirstances? but..?

is only convenient due to the present cirstances--cirstances that are unusual? i need a word that would sum that up... that may be a tad bit confusing, so for example, a days-long onslaught of rain would be horribly annoying under usual cirstances. However, for a town where there hasn`t been rain for 3 years, the rain is convenient. if i need to clarify more, let me know...i`ll try! thanks in advance