howmuchsun

Daylight hours in Rio de Janeiro

Rio de Janeiro gets 13h 32m of daylight on its longest day in December, and 10h 44m on its shortest in June — a difference of 2h 48m across the year.

How fast the days change

Around 17 March, Rio de Janeiro gains or loses about 1.3 minutes of daylight every day.

Barely perceptible — near the equator the length of the day hardly changes at all, and the seasons announce themselves through rain and heat instead.

Sunrise and sunset by month

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

Sunrise, sunset and day length by month.
MonthSunriseSunsetDaylightSolar noon
January 05:20 18:43 13h 23m 12:02
February 05:41 18:32 12h 51m 12:06
March 05:54 18:08 12h 14m 12:01
April 06:05 17:39 11h 33m 11:52
May 06:18 17:19 11h 01m 11:49
June 06:31 17:15 10h 44m 11:53
July 06:33 17:24 10h 51m 11:58
August 06:17 17:36 11h 19m 11:57
September 05:49 17:46 11h 58m 11:47
October 05:20 17:56 12h 37m 11:38
November 05:00 18:13 13h 13m 11:37
December 05:02 18:33 13h 32m 11:47

Solstices and equinoxes

DateSunriseSunsetDaylight
March equinox 20 Mar 05:56 18:03 12h 07m
June solstice 21 Jun 06:32 17:16 10h 44m
September equinox 22 Sep 05:42 17:48 12h 07m
December solstice 21 Dec 05:04 18:37 13h 32m

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 Brazil

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