Several years ago I bought a rain gauge and attached it to a fencepost by my compost pile. The squirrels kept taking the tube out of the holder and eventually, I couldn't find it.
As an alternative, I started leaving a straight-sided water glass on a table in the center of the patio. When it rains, I measure the water in the glass and determine how much rain we received. My highly unscientific readings, however, are always much higher than what the weatherman on TV says, and when I tell my friends "we got an inch and a half of rain this morning," they sound like they don't believe me. All this leads me to wonder if I'm taking inaccurate readings?
I'm no science whiz, but it seems to me that it doesn't matter if the collection device is a small tube or my drinking glass - what matters is that the opening at the top is the same as the diameter at the bottom... an inch of rainfall should fill both containers to the same exact level - right?
Can anyone tell me what I'm doing wrong (or validate my theory)?
That should work fine, even allowing for improper reading of whatever instrument you use to measure, it should not be very far off. Remember that the official reading may be quite different, because it is located in a different weather pattern. In my case the official reading is taken at the airport 20 + miles away. It may rain there and not at all here or rain here and miss there.
I agree with Farmerdill. Rain is not uniform. Even quite close to it can be very different. I'll always remember sitting once on a roadside bench watching it pouring with rain less than a hundred yards away while I sat in bright sunshine,
Yeah, I know the weather pattern can vary greatly across town, but it just seems like my unscientific glass always has more rain than the stats they quote on TV, even when they mention my neighborhood. I'm going to call my readings "correct" unless someone else can find a flaw in the observation.
We always seem to get more rain than the weather report states. We've gone through a few different rain measuring gadgets, which either break due to being plastic or they get knocked down by the squirrels.
One day I came in the back kitchen door, fairly wet from the rain, and my husband was sitting at the opposite end of the kitchen looking out at the courtyard, which remained totally dry. Now that it's happened more than once a year it's no longer an oddity.