Seasonal figures below use a 2025 reference year. Choose a date in the planner above for that day’s times, golden hour, twilight, and daylight milestones.
Seasonal Sun Milestones in Mount Vernon
Mount Vernon's 9 PM sunsets run from about May 29 to July 21 — 54 evenings in a typical year. The wider season of sunsets at 7 PM or later lasts 201 days, from March 9 to September 25. At the other end of the year, sunsets before 4:30 PM begin around November 16 and last until January 4.
Days in Mount Vernon first reach 12 hours of daylight around March 17, a few days before the March equinox, and drop back under 12 hours after September 24. Days with at least 15 hours of daylight run from May 10 to August 1. Days with less than 9 hours of daylight run from November 20 to January 20 (62 days).
The Sun's rising point moves along the horizon too. Around the June solstice it rises in the NE (52°) and sets in the NW (308°); by the December solstice it rises in the SE (126°) and sets in the SW (234°). That is a 74° swing — worth knowing when choosing a west-facing viewpoint for a summer sunset or an east-facing window for winter morning light.
Dates use the 2025 reference year. Clock-time milestones near daylight-saving changes move with the second Sunday in March and the first Sunday in November.
Daylight Through the Year in Mount Vernon
Mount Vernon lies at 48.42°N, high enough in latitude that residents feel the seasons clearly in the length of the day. Between the summer and winter solstice, daylight in Mount Vernon changes by 7h 48m.
On the summer solstice around June 21, Mount Vernon receives 16h 7m of daylight — the longest day of the year. By the winter solstice around December 21, that shrinks to 8h 19m, the shortest day. At the spring and autumn equinoxes, day and night are nearly equal at about 12h 12m, as they are everywhere on Earth.
Sunset moves fastest around September, when it shifts by up to 2.1 minutes a day in Mount Vernon, and barely moves for weeks around the solstices. See how sunrise and sunset change through the year for why.
The Sun's Path Over Mount Vernon
Where the Sun sits in the sky over Mount Vernon depends on the season, and the contrast between summer and winter is set by the city's latitude of 48.42°N. On the summer solstice the midday Sun reaches 65.0° above the horizon in Mount Vernon, its highest point of the year. On the winter solstice the midday Sun only reaches 18.2°, sitting much lower in the southern sky and casting long shadows even at noon.
Those roughly 47 degrees separating the summer and winter midday Sun are exactly what give Mount Vernon its seasons.
The live sun path at the top of this page shows the Sun's altitude and compass bearing for the current moment or any chosen date.
Earliest and Latest Sunrises and Sunsets in Mount Vernon
It is natural to assume Mount Vernon sees its latest sunset on the longest day of the year, but it does not. The latest sunset actually falls around June 25 at about 9:15 PM, while the earliest sunset comes around December 11 at roughly 4:14 PM — noticeably before the December solstice.
On the morning side, the earliest sunrise in Mount Vernon is around June 16 at 5:07 AM, and the latest sunrise around December 31 at 8:01 AM. The equation of time and daylight saving pull these dates away from the solstices — explained in why the latest sunset isn't on the longest day.
How Daylight Saving Time Moves Sunrise and Sunset in Mount Vernon
Mount Vernon, Washington changes its clocks twice a year, and both changes are visible in this page's numbers. On the second Sunday in March, Mount Vernon springs forward and the evening changes overnight: sunset jumps from about 6:05 PM on Saturday to about 7:06 PM on Sunday. The price is paid at dawn — sunrise slips from around 6:36 AM back to 7:34 AM, so mornings turn dark again just as they were brightening.
The reverse comes on the first Sunday in November, when clocks fall back: sunset drops from about 5:49 PM to 4:48 PM in a single day — the abrupt start of the early-dusk season — while sunrise brightens from around 7:56 AM to 6:57 AM.
Only the clock label shifts on those Sundays; the times above are for a typical year. More in how daylight saving time changes sunrise and sunset.
Golden Hour & Blue Hour Photography in Mount Vernon
For photographers in Mount Vernon, Washington, the planner shows your selected date's morning and evening golden-hour and blue-hour windows. Choose Today, Tomorrow, or a date in the calendar; all clock times are calculated in Mount Vernon's local timezone.
Golden "hour" is a misnomer — its length in Mount Vernon depends on the season, because it lasts as long as the Sun takes to climb from the horizon to 6° (or descend back). Around the equinoxes it runs about 41 minutes; near the June solstice, when the Sun rises and sets at a shallower angle, it stretches to roughly 49 minutes, and near the December solstice it lasts about 55 minutes.
See the golden hour guide and blue hour guide for how to plan a shoot around these windows.
Solar Energy Potential in Mount Vernon
Under clear skies, Mount Vernon, Washington receives about 4.4 peak sun hours per day averaged across the year — from roughly 1 in December up to 8.1 in June. One peak sun hour equals one hour of sunlight at full intensity (1 kW/m²), the standard unit for estimating solar panel output.
Because Mount Vernon sits at 48.4°N, a fixed, south-facing panel captures the most energy over the year when tilted at roughly 48° from horizontal — about equal to the latitude. If you adjust the tilt seasonally, flatten to about 33° in summer, when the Sun rides high, and steepen to about 63° in winter, when it stays low.
These are clear-sky upper bounds from Mount Vernon's solar geometry, not a forecast; clouds, shading, and equipment lower real output. See what peak sun hours mean.
How Mount Vernon Compares
Daylight in Mount Vernon swings 7h 48m between the June and December solstices. The median across the 1,847 cities on this site is 5h 16m, so the seasons move the clock 2h 32m further in Mount Vernon than in a typical American city. By that measure Mount Vernon ranks 5th of 1,847 nationally, and 2nd of the 52 Washington cities listed here — counting from the largest swing down.
Mount Vernon sits about 2.3° west of 120°W — the meridian Pacific Time is built around. Longitude alone therefore puts mean solar noon roughly 9 minutes after clock noon in standard time, so the Sun runs behind the clock here, which is why evenings hold light later than the time zone would suggest. The equation of time then moves true solar noon up to about 16 minutes either side of that through the year.
About Sun Times in Mount Vernon
Mount Vernon, Washington, has an estimated urban-area population of 69,561. Its primary county or equivalent is Skagit; its center is at 48.42°N, 122.31°W. Clocks here follow Pacific Time, which is the timezone all sunrise, sunset, golden-hour and twilight times on this page are shown in.
Times are computed for Mount Vernon's city-center coordinates, so towns to the east see each event slightly earlier and towns to the west slightly later; the nearby-cities list above shows the typical gap.