Welcome to
Fermilab's weather data site (provided by the Environmental Protection Group of
the ESH&Q Section). Fermilab’s meteorological (met) station became
operational in 1992. Located in open field, the station is completely solar
powered and consists of a 30-foot tower (as of September 2002) to which the
following instruments are attached: temperature and relative humidity sensor,
tipping-bucket rain gauge, combined wind speed and direction sensor, barometer,
and pyranometer. The station’s geographical location is North 41º 51'
22.5", West 88º 14' 19.0" at an elevation of 740.7 feet above Mean
Sea Level (MSL).
See an aerial photo of its location (near New Muon
Lab) on site.
An electronic data
logger at the station is programmed to record measurements from each sensor
once a second and report current conditions with hourly and daily summaries
including selected maximums, minimums, and averages. Monthly summaries are
generated from these. The “Current Conditions” frame
(left) displays these measurements updated every minute. In addition, heat
index and wind chill are calculated and displayed, as applicable. The current
hour precipitation is reset at the top of each hour. To view the archive
data select a year from the drop-down menu and click Submit. This will display
the monthly summaries for that year. View daily data by clicking on a specific
month. To view hourly data for a certain day, click on that day. Presently,
there is about a month delay between archive data updates, as these must be
collected manually.
Precipitation data
are collected by the tipping-bucket rain gauge. Previously a weighing-bucket
rain gauge (installed May 1993) provided analog precipitation data for the
snow-producing months. That gauge recorded events on a paper chart requiring
replacement and manual database entry on a weekly basis. In January 2002, the
tipping-bucket rain gauge was upgraded to include the capability of providing
precipitation data during the snow-producing months. At that time the
weighing-bucket rain gauge was taken out of service. Depending on the air
temperature and the intensity of sunlight, some delay may exist between a snow
event and the data recording.
The
dew point temperature is calculated based on measurements of temperature and
relative humidity. Relative humidity is the ratio of the amount of water vapor
in the air to the maximum amount of water vapor the air can hold (for a given
temperature), expressed as a percentage. Dew point temperature is the temperature
at which the relative humidity equals 100% and moisture in the air can condense
to create fog.
The pyranometer
measures solar radiation (sunlight) for the hemisphere of sky above the sensor,
and reports it as an average flux density in W/m².
See
the relationship between solar radiation and air temperature throughout a year.
View data recorded
during a solar eclipse.
The “Wind Gust” measurement
is the maximum wind speed in the previous minute recorded.
The wind direction
sensor measures the wind direction in degrees. If the measurement is 0º, the
wind is from the north. If the measurement is 90º, the wind is out of the east.
The met station is oriented where 0º is “true” north. True north is the Earth’s
northern rotational axis, as opposed to magnetic north, which varies through
time.
Questions,
Questions, Questions
Q. Why does
Fermilab have a meteorological station?
A. The primary
purpose of the met station is to provide data for compliance with 40 CFR
61.93(a) Emission Monitoring and Test Procedures. Additionally, it provides
precipitation information to construction managers for post-storm erosion
control inspection requirements at on-site construction projects. Over the
years people have found various other uses. Aside from regulatory purposes: it
assists the physics mission of the Lab by providing data to Accelerator
Division for correlation of expansion/contraction of accelerator components to
environmental conditions. Providing wind conditions can aide Roads and Grounds
in prairie burn safety with respect to smoke dissipation. Meteorological data
also can support recreational activities by providing on-site conditions to
model-aircraft enthusiasts (The Fermilab
Barnstormers) at the Frelo Flying Field.
Q. Why isn’t the
time adjusted for daylight saving?
A. Adjusting the
time would create a one-hour data gap in spring while in autumn one hour would
be repeated. This complicates the importation of data into software modeling
programs and can create unexpected issues for assorted automated systems using
the data. Additionally, by leaving the time as Central Standard Time (CST) an
entire data set can easily be converted to Coordinated Universal Time (UTC) by
adding six (6) hours to each time.
Q. What was the
highest wind speed, coldest temperature, etc. recorded at Fermilab?
A.
Weather Images
Above images previously published in Fermilab Today.
Weather-Related
Links
Current Conditions
& Forecast at Batavia, IL (weather.com)
Current
Weather Conditions at Aurora Municipal Airport (National Weather Service)
Illinois
State Climatologist’s Office – Illinois State Water Survey (ISWS)
National Oceanic
and Atmospheric Administration (NOAA) Home Page
National
Weather Service Enhanced Radar Image Loop for the Chicago, IL area
National
Weather Service Forecast Office for Chicago, IL
NOAA
Weather Radio for Northeastern Illinois live on the Web!
Severe
Weather at Fermilab (.pdf file)
Subscribe
to receive National Weather Service (NWS) alerts (for Northeastern Illinois)
via email.
United
States Geological Survey (USGS) National Water Information System
Wind
Chill Chart or Heat
Index Chart (.pdf files) (provided by NOAA)
Disclaimer:
Data provided pertain exclusively to the Fermilab Meteorological Station and do
not constitute “official” measurements. All data are provided “as is” for
general informational purposes only. Any other use is at your own risk.
Please contact us any
questions or comments.
Page last updated: May 5, 2013