howmuchsun

Daylight hours in Simi Valley

Simi Valley gets 14h 26m of daylight on its longest day in June, and 9h 53m on its shortest in December — a difference of 4h 33m across the year.

How fast the days change

Around 17 March, Simi Valley gains or loses about 2.2 minutes of daylight every day.

Enough to notice over a fortnight, though the seasons arrive more gently here than further from the equator.

Sunrise and sunset by month

On the 15th of each month, in America/Los_Angeles local time, daylight saving included.

Sunrise, sunset and day length by month.
MonthSunriseSunsetDaylightSolar noon
January 07:00 17:08 10h 08m 12:04
February 06:39 17:38 10h 59m 12:09
March 07:05 19:02 11h 58m 13:03
April 06:23 19:26 13h 03m 12:55
May 05:52 19:50 13h 57m 12:51
June 05:42 20:08 14h 26m 12:55
July 05:54 20:07 14h 13m 13:01
August 06:16 19:42 13h 26m 12:59
September 06:38 19:01 12h 23m 12:50
October 07:00 18:20 11h 20m 12:40
November 06:28 16:50 10h 22m 11:39
December 06:54 16:46 9h 53m 11:50

Solstices and equinoxes

DateSunriseSunsetDaylight
March equinox 20 Mar 06:58 19:06 12h 08m
June solstice 21 Jun 05:43 20:10 14h 27m
September equinox 22 Sep 06:43 18:52 12h 09m
December solstice 21 Dec 06:57 16:49 9h 52m

The equinoxes give almost exactly twelve hours of daylight everywhere on earth — "almost" because sunrise is defined by the sun's upper edge rather than its centre, and the atmosphere bends its light over the horizon before it has really arrived. Both lengthen the day by a few minutes.

Other cities in United States

Assumptions

  • Sea-level horizon. Hills, mountains and buildings all delay sunrise and bring sunset forward, sometimes by a lot in a valley.
  • Standard refraction. Sunrise is taken at −0.833°, allowing for the sun's disc and average atmospheric bending. Unusual air conditions shift it by a minute or two.
  • Local clock time, with daylight saving applied from the IANA timezone database.

Full methodology, sources and known limitations