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 Casper
Casper's 8 PM sunsets run from about April 25 to August 19 — 117 evenings in a typical year. The wider season of sunsets at 7 PM or later lasts 199 days, from March 9 to September 23. At the other end of the year, sunsets before 5 PM begin around November 2 and last until January 17.
Days in Casper first reach 12 hours of daylight around March 17, a few days before the March equinox, and drop back under 12 hours after September 25. Days with at least 15 hours of daylight run from May 27 to July 15. Days with less than 10 hours of daylight run from November 8 to February 1 (86 days).
The Sun's rising point moves along the horizon too. Around the June solstice it rises in the NE (56°) and sets in the NW (304°); by the December solstice it rises in the ESE (122°) and sets in the WSW (238°). That is a 66° 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 Casper
Casper sits at 42.84°N, a mid-latitude position that gives it a balanced but noticeable seasonal rhythm. The difference between its longest and shortest day is 6h 19m.
On the summer solstice around June 21, Casper receives 15h 21m of daylight — the longest day of the year. By the winter solstice around December 21, that shrinks to 9h 1m, the shortest day. At the spring and autumn equinoxes, day and night are nearly equal at about 12h 10m, as they are everywhere on Earth.
Sunset moves fastest around September, when it shifts by up to 1.8 minutes a day in Casper, and barely moves for weeks around the solstices. See how sunrise and sunset change through the year for why.
The Sun's Path Over Casper
Where the Sun sits in the sky over Casper depends on the season, and the contrast between summer and winter is set by the city's latitude of 42.84°N. On the summer solstice the midday Sun reaches 70.6° above the horizon in Casper, its highest point of the year. On the winter solstice the midday Sun only reaches 23.8°, 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 Casper 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 Casper
It is natural to assume Casper sees its latest sunset on the longest day of the year, but it does not. The latest sunset actually falls around June 26 at about 8:48 PM, while the earliest sunset comes around December 8 at roughly 4:31 PM — noticeably before the December solstice.
On the morning side, the earliest sunrise in Casper is around June 14 at 5:26 AM, and the latest sunrise around November 1 at 7:40 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 Casper
Casper, Wyoming changes its clocks twice a year, and both changes are visible in this page's numbers. On the second Sunday in March, Casper springs forward and the evening changes overnight: sunset jumps from about 6:04 PM on Saturday to about 7:05 PM on Sunday. The price is paid at dawn — sunrise slips from around 6:29 AM back to 7:27 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 5:57 PM to 4:56 PM in a single day — the abrupt start of the early-dusk season — while sunrise brightens from around 7:40 AM to 6:41 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 Casper
For photographers in Casper, Wyoming, 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 Casper's local timezone.
Golden "hour" is a misnomer — its length in Casper 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 37 minutes; near the June solstice, when the Sun rises and sets at a shallower angle, it stretches to roughly 43 minutes, and near the December solstice it lasts about 46 minutes.
See the golden hour guide and blue hour guide for how to plan a shoot around these windows.
Solar Energy Potential in Casper
Under clear skies, Casper, Wyoming receives about 4.9 peak sun hours per day averaged across the year — from roughly 1.6 in December up to 8.2 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 Casper sits at 42.8°N, a fixed, south-facing panel captures the most energy over the year when tilted at roughly 43° from horizontal — about equal to the latitude. If you adjust the tilt seasonally, flatten to about 28° in summer, when the Sun rides high, and steepen to about 58° in winter, when it stays low.
These are clear-sky upper bounds from Casper's solar geometry, not a forecast; clouds, shading, and equipment lower real output. See what peak sun hours mean.
How Casper Compares
Daylight in Casper swings 6h 19m 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 1h 3m further in Casper than in a typical American city. By that measure Casper ranks 219th of 1,847 nationally, and 2nd of the 4 Wyoming cities listed here — counting from the largest swing down.
Casper sits about 1.3° west of 105°W — the meridian Mountain Time is built around. Longitude alone therefore puts mean solar noon roughly 5 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 Casper
Casper, Wyoming, has an estimated urban-area population of 65,842. Its primary county or equivalent is Natrona; its center is at 42.84°N, 106.32°W. Clocks here follow Mountain Time, which is the timezone all sunrise, sunset, golden-hour and twilight times on this page are shown in.
Times are computed for Casper'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.