Located in Blue Earth County, Minnesota, Alumni Arch and Plaza is a natural arch at about 308 m (1,010 ft) above sea level. The nearest town is Mankato, about 1.7 km (1.1 mi) away (Alumni Arch and Plaza lies SE of town).
Sunrise & sunset directions
At Alumni Arch and Plaza the sunrise point swings a long way through the year: about 56° (NE) at the June solstice and 123° (ESE) in late December. Sunset moves from 305° (NW) in June to 237° (WSW) in December, and the midday sun climbs to 69° in summer but only 22° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:20 AM | 90° E | 7:28 PM | 271° W | 46° | 12h 08m |
| June solstice (Jun 21) | 5:33 AM | 56° NE | 9:04 PM | 305° NW | 69° | 15h 30m |
| September equinox (Sep 22) | 7:04 AM | 89° E | 7:15 PM | 271° W | 46° | 12h 11m |
| December solstice (Dec 21) | 7:49 AM | 123° ESE | 4:41 PM | 237° WSW | 22° | 8h 52m |
Azimuth is measured clockwise from true north (90° = east, 270° = west). Computed for 2026; values change by less than a degree from year to year.
Golden hour & blue hour by month
Arches glow when reflected light bounces off nearby rock — the underside of an arch often turns bright orange just after sunrise or before sunset.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 7:16 AM | 7:49 AM | 8:34 AM | 4:18 PM | 5:03 PM | 5:36 PM | 9h 15m |
| February | 6:47 AM | 7:16 AM | 7:57 AM | 5:05 PM | 5:46 PM | 6:15 PM | 10h 29m |
| March | 7:00 AM | 7:29 AM | 8:08 AM | 6:44 PM | 7:22 PM | 7:51 PM | 11h 53m |
| April | 6:03 AM | 6:33 AM | 7:12 AM | 7:21 PM | 8:00 PM | 8:30 PM | 13h 27m |
| May | 5:17 AM | 5:50 AM | 6:32 AM | 7:54 PM | 8:36 PM | 9:10 PM | 14h 46m |
| June | 4:56 AM | 5:33 AM | 6:17 AM | 8:18 PM | 9:02 PM | 9:38 PM | 15h 29m |
| July | 5:12 AM | 5:47 AM | 6:30 AM | 8:15 PM | 8:58 PM | 9:33 PM | 15h 11m |
| August | 5:49 AM | 6:20 AM | 7:00 AM | 7:43 PM | 8:22 PM | 8:54 PM | 14h 02m |
| September | 6:27 AM | 6:56 AM | 7:34 AM | 6:50 PM | 7:28 PM | 7:57 PM | 12h 33m |
| October | 7:02 AM | 7:31 AM | 8:11 AM | 5:54 PM | 6:34 PM | 7:03 PM | 11h 02m |
| November | 6:41 AM | 7:12 AM | 7:56 AM | 4:07 PM | 4:51 PM | 5:22 PM | 9h 39m |
| December | 7:12 AM | 7:45 AM | 8:33 AM | 3:51 PM | 4:39 PM | 5:12 PM | 8h 54m |
Local time (America/Chicago), including daylight saving time. Golden hour runs from about −4° to +6° solar altitude, so the morning golden hour begins during blue hour, before sunrise.
Milky Way & night sky
From Alumni Arch and Plaza, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 3.5 hours on a moonless night), and the core peaks around 17° above the southern horizon. Our light-pollution model puts the sky at about Bortle 7 (suburban / urban transition), so expect visible sky glow; drive away from towns for better results.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -5° | — |
| February | Below 10° in darkness | — | 8° | — |
| March | 5:09 AM – 5:49 AM | 0.7 | 13° | SSE → SSE |
| April | 3:06 AM – 4:36 AM | 1.5 | 16° | SSE → S |
| May | 1:12 AM – 3:42 AM | 2.5 | 17° | SSE → S |
| June | 11:29 PM – 2:59 AM | 3.5 | 17° | SSE → SSW |
| July | 11:14 PM – 1:44 AM | 2.5 | 17° | S → SSW |
| August | 10:15 PM – 11:45 PM | 1.5 | 16° | S → SSW |
| September | 9:08 PM – 9:38 PM | 0.5 | 13° | SSW → SSW |
| October | Below 10° in darkness | — | 8° | — |
| November | Below 10° in darkness | — | -3° | — |
| December | Below 10° in darkness | — | -20° | — |
Window when the galactic core is at least 10° high during astronomical darkness on the 15th of each month. Pick nights within a few days of the new moon. Plan exact nights with the Milky Way planner.
Estimated sky darkness: 7 Bortle 7 — Suburban / urban transition. The whole sky has a grey-white glow; the Milky Way is invisible to the eye. Modeled zenith brightness ≈ 18.76 mag/arcsec². Aurora needs roughly Kp 5.0+ to show low on the northern horizon here.
Weather & best season
Long-term NASA satellite data for this area show July as the clearest month (about 46% average cloud cover) and December as the cloudiest (69%). July is the warmest month and January the coldest, which matters for gear, snow access and how long batteries last at night.
Average cloud cover (%)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High °F | 50 | 61 | 80 | 89 | 96 | 96 | 107 | 100 | 96 | 87 | 78 | 61 |
| Low °F | -37 | -27 | -23 | 4 | 24 | 41 | 46 | 43 | 32 | 12 | -4 | -24 |
| Precip. (in) | 0.6 | 1.1 | 1.7 | 3.1 | 4.1 | 4.8 | 3.5 | 3.7 | 3.4 | 2.3 | 1.2 | 1.2 |
Monthly climatology for the surrounding 1° grid cell from NASA POWER (MERRA-2). Mountain sites can be colder and cloudier than the cell average.
Photography tips for this natural arch
- Use a wide lens and get close to emphasize the span against the sky.
- Never climb on arches; many are fragile and climbing is prohibited on park lands.
- Midday sun creates hard shadows, but can light the underside through reflection in narrow canyons.
- Frame distant features through the opening of the arch for a natural window.
- Check road and trail conditions with the managing agency before you go.
Season: Spring and autumn offer mild temperatures in desert arch country; summer heat is extreme at midday.
Suggested gear: Ultra-wide lens, Tripod, Headlamp, Plenty of water. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Alumni Arch and Plaza, closest first.
Waterfall
Waterfall
State ParkWaterfall
Botanical GardenFAQ
When is the best time to photograph Alumni Arch and Plaza?
What time is golden hour at Alumni Arch and Plaza?
Where does the sun rise and set at Alumni Arch and Plaza?
Can you see the Milky Way from Alumni Arch and Plaza?
Do you need a permit to photograph at Alumni Arch and Plaza?
How far is Alumni Arch and Plaza from Mankato?
Sources
Location data: USGS GNIS / GeoNames. Sun, moon and Milky Way times are computed by LWPhoto Atlas for 2026. Climate: NASA POWER. Sky darkness is a population-based estimate (Walker's law), not a measurement. See data sources & licenses.