But identifying the moment when a dry spell becomes a "drought" is more personal and subjective.
The formal declaration varies from place to place because different locations historically expect differing amounts of water.
And of course different people see things selfishly.
Did I say "selfishly"? I meant "differently". Oops.
Here's a little rhyme to sum it up:
If there's one thing we needn't doubt,
it's when to call a drought 'a drought'.
The standard measures tell us why
It's drought, and not 'a little dry'.
'A little dry' is what you've got
when farmers say 'The field's too hot.'
Or forest rangers, dripping sweat
Suggest the trees 'could use some wet'.
'A little dry' is the annoyance
buoys feel, not needing buoyance
And 'dry' is when a mink will slip
Into a your birdbath for a sip.
But if you hear 'It isn't raining!'
That's not drought. It's just complaining.
For drought is quite another deal.
A drought's a crisis, stark and real
You know for sure a drought is on
When I've got brown spots on my lawn.
So ... I've definitely got a drought at my house. How about you?