About This Station

The data you see presented here is generated by a private weather station which currently resides in a residential yard in North Grafton, MA, USA.

As of May 31, 2102, the data you see from this weather station was collected by a Davis Vantage Pro 2 weather station with a fan aspirated radiation shield. The data is collected approximately every 5 seconds and the site is updated every 5 minutes. If you have JavaScript enabled in your browser, you will see the data updating in real time when you first arrive at this site - this real-time data will continue for 2 minutes and then stop until the page is refreshed.

Data Collection - The Software & Hardware

Data for this site is collected via an Ambient Weather WeatherHub 2 dedicated weather server, which runs the excellent MeteoHub software, written by Boris Pasternak, ported to a SheevaPlug platform. The station is comprised of an anemometer, a rain gauge and a thermo-hydro sensor situated in optimal positions for highest accuracy possible given the constraints of my yard.

As good as the Davis hardware is, meteorological measurement accuracy is largely affected by the siting of sensors and the geography of the surrounding terrain. I have tried to mount my station in the optimal location given the constraints of my property, but any such mounting will always be a compromise. In its current configuration, the anemometer for my station is located on a mast at a height of 25 feet (which it shares with a tri-band VHF ham radio antenna), mounted to the gable of my garage roof. The thermometer, humidity sensor, and rain collector are mounted near the bottom of that mast at a height of 15 feet.

Compromises Due to Location

My yard is surrounded by very tall mature trees. Because of this, even at 25 feet, I suspect my anemometer provides wind values that are too low when compared to a sensor sited in the open, particularly in the summer months when the trees are in full foliage. Nonetheless, I believe it provides an accurate measurement of the actual wind affecting us on the ground, even if it isnít meteorologically perfect. Additionally, the main roof of my house is nearby and the anemometer is barely higher than that roof, so I suspect winds from the south or southwest will be measured inaccurately. Fortunately, the wind around here rarely blows from southerly directions.

Because itís mounted on the roof of my garage, the temperature sensor is subject to inaccurate readings due to the solar heating of the nearby roof materials. I believe I have minimized this effect as much as practical because:

  1. The sensor is mounted in a radiation shield. Radiation shields are designed to reduce the effects of re-radiated heat on temperature measurements.
  2. The shield is fan-aspirated. This means that air is drawn through the shield and over the sensor 24 hours a day by a fan. This should help to further reduce the affects of the heating of air from the nearby roof.
  3. Iíve sited the sensor on the East side of my home, so that it is near a structure that receives direct sun only in the morning hours and not when the sun is the most intense.

Data Quality Checking

In spite of these limitations, I strive for accuracy in my data. In order to ensure that the data I collect are accurate, I submit them to quality control checking by NOAA's Citizen Weather Observer Program (CWOP) under the station identifier AS792. You can see the results of the continuous quality control checks on my Data Quality page.

About This City

Grafton Massachusetts is a town in Worcester County, in central Massachusetts. It was settled bt Europeans in 1718 and formally incorporated in 1735. Originally home to bands of the Nipmuc tribe, Grafton is now home to the 4.5 acre Hassanamesit Reservation, land which has remained in posession of the Nipmuc nation for more than 200 years.

About This Website

This site is a template design by CarterLake.org with PHP conversion by Saratoga-Weather.org.
Special thanks go to Kevin Reed at TNET Weather for his work on the original Carterlake templates, and his design for the common website PHP management.
Special thanks to Mike Challis of Long Beach WA for his wind-rose generator, Theme Switcher and CSS styling help with these templates.
Special thanks go to Ken True of Saratoga-Weather.org for the AJAX conditions display, dashboard and integration of the TNET Weather common PHP site design for this site.

Template is originally based on Designs by Haran.

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