GMARS Weather Center

34° 17' 26.33" N (34.29055556), 116° 23' 01.77" W (-116.38388889)   |   ELEVATION IS 2,937'
WU Forecast | NWS Forecast | Radar | NWS 3-Day History
Star Chart | Sun/Moon Data | Satellite Predictions

Sky quality magnitude per square arcsecond (mag/arcsec²) is a unit used to measure the brightness (or darkness) of the night sky. This value can then be converted to a more familiar, yet theoretical, Naked-Eye Limiting Magnitude (NELM) value. Values of 20+ indicate a dark sky, good for astronomical endeavors (mag/arcsec² of 20.8 equals a NELM of 6.0, roughly).

The sky quality data is measured every 5 minutes between the end of astronomical dusk and the beginning of astronomical dawn. Plots represent 15-minute averages of the individual readings.

GMARS is located in the Mojave Desert not too far from Joshua Tree National Park. The weather information provided on these pages can be useful in guiding your travel and observing plans. Keep in mind the weather can change drastically in a short amount of time. Use the Forecast and Trend Graphs pages to find out what the wind and temperature have been doing for the last 24 hours.

GMARS current and historical weather data is provided by the club's Davis Instruments Vantage Pro² weather station mounted on the GMARS West property. Forecast links go to Weather Underground and the National Weather Service websites. Sun and moon information is provided by Der-Mond.de.

This page, the Trends page, and the forecast links should provide you with plenty of data to allow you to plan (or cancel) your trip to GMARS accordingly.