The following plots show the sunrise, local noon and sunset times for Fallbrook, CA, using daylight time when applicable, which accounts for the 1 hour jumps in the times near the beginning of April and the end of October. The data were obtained from the US Naval Observatory specifically for the location of Fallbrook (W117o 21', N33o 23') from USNO Sunrise/Sunset Computation.
The times for anyplace in San Diego County will not vary by more than 2-3 minutes from those values. (For example, compare with the sunrise/sunset times for Pasadena, CA, which is ~52 miles north and ~52 miles west of Fallbrook, a greater distance than anyplace in San Diego County from Fallbrook.)
Local noon is the time on your watch when the sun is actually at its highest position in the sky and appears due south. This time is different from 12:00 standard time for two reasons:
The Equation of Time also explains why the earliest sunset occurs in early December and the latest sunrise in early January, a month apart.
See Bob Urschel's wonderful explanation of the Equation of Time and the Analemma.
Note the amazing thing that we have done with daylight savings time: we have made the range of sunset 3.25 hours, while keeping the range of sunrise to less than 1.5 hours.
The final plot below shows the times at which the UV reaches 0.4 times the maximum level it ever reaches (at noon on June 21). The value 0.4 was picked because that corresponds closely with the conventional wisdom to "stay out of the sun between 9 a.m. and 3 p.m.". Note that this advice refers to local noon, not noon daylight savings time, and is only really valid for May 21 to July 21. During other months, that same UV level is reached only much closer in time to local noon.
![]() (Click on graph for bigger and better image.) | ![]() (Click on graph for bigger and better image.) |
Go to Fallbrook Information Overview
Copyright © 1997-1999 by Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to me at this source:
http://sd.znet.com/~schester/fallbrook/weather/sunrise.html
Comments and feedback: Tom Chester
Last update: 23 January 2000