APL Weather
[Historical APL Weather | APL Extreme Precipitation Statistics | APL Weather Station | APL Physical Data | APL Sunrise/Sunset Times]

Historical APL Weather

Historical APL weather observations are archived from June 13, 1996 to January 31, 2012. APL archived observations are available as:

•  APL daily station records [Link]

•  APL monthly station records [Link]

•  Daily files [Link]

•  Monthly files - summaries (e.g., high and low temperatures, precipitation totals) for each day of the month [Link]

•  Monthly quick-look file - a summary of averages, extremes, and precipitation totals for each month [Link]

•  Yearly files - the "Monthly files" for each year merged into one file for that year [Link]

•  Freeze data for agricultural interests [Link]

•  Snow data observations by season, month, and event [Link]

•  Precipitation data observations by month and year [Link]

•  Drought monitor data

     •  Precipitation differences from "normal" (inches) [Link]

     •  Precipitation differences from "normal" (inches) - color version [Link]

     •  Percent of "normal" precipitation [Link]

•  Heating and cooling degree days

     •  Seasonal summary [Link]

     •  Seasonal cumulative totals, month by month [Link]

•  Peak wind gust data summary by month [Link]

APL Extreme Precipitation Statistics

A table of extreme precipitation statistics based on regional climatological studies performed at Cornell University is available for APL's location in Laurel, MD. The data in the table express extreme precipitation amounts corresponding to "average return periods" for 15-minute, 30-minute, 1-hour, 2-hour, 3-hour, 6-hour, 12-hour, 18-hour, 24-hour, and 48-hour precipitation totals. Click here to see this table.

APL Weather Station

The APL weather station closed on January 30, 2012.

APL Physical Data

Listed below is a compilation of useful physical data about APL.

Latitude and Longitude

The point of reference for APL's geographical location is the original 1954 geodetic survey marker located within the ellipse in front of Building 1. This reference point was surveyed at:

39° 09' 45.5" N latitude (39.16264° N)

76° 53' 59.5" W longitude (76.89986° W)

Plant Engineering can provide more specific latitude and longitude coordinates for other locations within APL's borders if more detail is required.

Magnetic Variation

In our hemisphere, magnetic compasses point to the magnetic north pole, not the geographical north pole or "true north." (The magnetic north pole is located in northern Canada at about 73° N latitude, 100° W longitude. This location varies very slowly over time.) Therefore, in the majority of locations in this hemisphere, the magnetic variation or angular difference between magnetic and geographic north is nonzero. For APL, the magnetic variation is approximately 10.5° west. This means that our compass here points in a direction approximately 10.5° west of true north. Therefore, true north is located about 10.5° east ("to the right") of where our compass points.