July 21, 2026 · Viana do Castelo, Portugal
Sunset in Viana do Castelo today is at 21:05. Day length is 14h 46m. See below for sunrise, solar noon, dawn and dusk — all times calculated astronomically for Viana do Castelo's coordinates and updated daily.
Viana do Castelo lies at 42°N. At this latitude, day length varies moderately — from around 10 hours in midwinter to 14–15 hours in midsummer.
Sunset shifts later through spring and earlier through autumn — changing fastest near the equinoxes and slowest near the summer and winter solstices. See the year chart to visualise how sunset times shift month by month for Viana do Castelo.
The longest day in Viana do Castelo is around 15h 12m (around June 21). The shortest is around 9h 9m (around December 21). Days are currently getting shorter — losing about 2 minutes per day.
| Month | Sunset | Sunrise | Day length |
|---|---|---|---|
| January | 17:29 | 08:01 | 9h 27m |
| February | 18:07 | 07:33 | 10h 34m |
| March | 18:41 | 06:50 | 11h 51m |
| April | 20:15 | 06:58 | 13h 17m |
| May | 20:47 | 06:18 | 14h 29m |
| June | 21:12 | 06:01 | 15h 11m |
| July | 21:10 | 06:14 | 14h 56m |
| August | 20:39 | 06:43 | 13h 55m |
| September | 19:49 | 07:15 | 12h 34m |
| October | 18:57 | 07:47 | 11h 11m |
| November | 17:17 | 07:24 | 9h 54m |
| December | 17:06 | 07:55 | 9h 11m |