One of the many things that we do at the US National Arboretum is keep Weather Records. We keep daily data. The picture shows the monthly sheet for June 2008. Seems primitive doesn't it. Handwritten and all. We record the high and low temperatures, the precipitation type and amount, and conditions at observation (we do the weather at 8:00 AM 365 or 366 days a year.
We use a recording digital thermometer, but we measure rainfall from a standard rain gauge and we have to look at the sky manually. Joke, sorry. We submit the data to NOAA via the internet daily, but still keep these sheets!
If you click on the page you will be able to see in the farthest column to the right, the cumulative monthly rainfall: 7.72". Thats a lot for June, or for any month for that matter. Normal rainfall for the month at Reagan National Airport is 3.13". Though we have more than doubled that, we are only halfway to the record high which is 14.02" and which was recorded only two years ago. The driest June on record was 1940 where they measured only .86"; we approached that minimum record last year with 1.36".
Anyway its a wet year, our year to date precipitation is over 30" and that's over 2/3 of what we would expect to get in a year. It only took 6 months and we seem to be in a pattern from which we can expect more. In Fern Valley, and I assume throughout the rest of the Arboretum (and in the Adelphi Garden) we have not had to do supplemental watering yet. By this time last year, the hoses and the rainbirds had had a good workout. That's the good news, on the down side is the fact that the numbers of weeds are unprecedentedly high and they are reaching remarkable sizes. Oh well. I would rather weed than water.