Cahokia is a state park in Madison County, Illinois. It lies in or next to Gateway Arch National Park, so park hours, fees and rules apply. It sits roughly 2.5 km (1.6 mi) E of Fairmont City. It is listed on the National Register of Historic Places.
The Cahokia Mounds (also simply known as Cahokia ; Smithsonian trinomial ID 11 MS 2) is the site of a Native American city which existed c. 1050 – c. 1350 AD, directly across the Mississippi River from present-day St. Louis. The state archaeology park lies in south-western Illinois between East St. Louis and Collinsville. The park covers 2,200 acres (890 ha; 3.4 mi2; 8.9 km2), and contains about 80 manmade mounds, but the ancient city was much larger. At its apex around 1100 AD, the city covered about 6 square miles (16 km2), included about 120 earthworks in a wide range of sizes, shapes, and functions, and had a population of between 15,000 and 20,000 people. Cahokia was the largest and most influential urban settlement of the Mississippian culture, which developed advanced societies across much of what is now the Central and the Southeastern United States, beginning around 1000 AD....From the Wikipedia article “Cahokia”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Cahokia the sunrise point swings a long way through the year: about 59° (ENE) at the June solstice and 120° (ESE) in late December. Sunset moves from 302° (WNW) in June to 240° (WSW) in December, and the midday sun climbs to 75° in summer but only 28° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:05 AM | 90° E | 7:12 PM | 271° W | 51° | 12h 08m |
| June solstice (Jun 21) | 5:37 AM | 59° ENE | 8:29 PM | 302° WNW | 75° | 14h 52m |
| September equinox (Sep 22) | 6:49 AM | 89° E | 6:59 PM | 271° W | 52° | 12h 10m |
| December solstice (Dec 21) | 7:15 AM | 120° ESE | 4:43 PM | 240° WSW | 28° | 9h 28m |
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
State parks often protect a signature feature — a gorge, lake or overlook — that is best in early morning before visitors and harsh light arrive.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 6:48 AM | 7:17 AM | 7:58 AM | 4:23 PM | 5:03 PM | 5:32 PM | 9h 46m |
| February | 6:25 AM | 6:52 AM | 7:29 AM | 5:01 PM | 5:38 PM | 6:06 PM | 10h 46m |
| March | 6:46 AM | 7:12 AM | 7:48 AM | 6:32 PM | 7:08 PM | 7:34 PM | 11h 55m |
| April | 5:57 AM | 6:25 AM | 7:00 AM | 7:01 PM | 7:37 PM | 8:04 PM | 13h 12m |
| May | 5:19 AM | 5:49 AM | 6:27 AM | 7:28 PM | 8:06 PM | 8:36 PM | 14h 16m |
| June | 5:04 AM | 5:36 AM | 6:16 AM | 7:47 PM | 8:27 PM | 8:59 PM | 14h 51m |
| July | 5:17 AM | 5:48 AM | 6:27 AM | 7:46 PM | 8:25 PM | 8:56 PM | 14h 37m |
| August | 5:47 AM | 6:15 AM | 6:51 AM | 7:20 PM | 7:56 PM | 8:25 PM | 13h 41m |
| September | 6:16 AM | 6:43 AM | 7:18 AM | 6:35 PM | 7:10 PM | 7:37 PM | 12h 28m |
| October | 6:43 AM | 7:10 AM | 7:46 AM | 5:47 PM | 6:23 PM | 6:50 PM | 11h 13m |
| November | 6:15 AM | 6:43 AM | 7:22 AM | 4:09 PM | 4:48 PM | 5:17 PM | 10h 05m |
| December | 6:42 AM | 7:12 AM | 7:54 AM | 3:59 PM | 4:41 PM | 5:11 PM | 9h 29m |
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 Cahokia, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 5.2 hours on a moonless night), and the core peaks around 22° above the southern horizon. Our light-pollution model puts the sky at about Bortle 6 (bright suburban sky), 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 | — | -2° | — |
| February | 5:07 AM – 5:17 AM | 0.2 | 12° | SE → SE |
| March | 4:16 AM – 5:36 AM | 1.3 | 19° | SE → SSE |
| April | 2:12 AM – 4:42 AM | 2.5 | 22° | SE → S |
| May | 12:13 AM – 3:53 AM | 3.7 | 22° | SE → S |
| June | 10:25 PM – 3:35 AM | 5.2 | 22° | SE → SSW |
| July | 10:18 PM – 2:08 AM | 3.8 | 22° | SSE → SW |
| August | 9:35 PM – 12:05 AM | 2.5 | 22° | S → SW |
| September | 8:40 PM – 10:00 PM | 1.3 | 19° | SSW → SW |
| October | 7:51 PM – 8:11 PM | 0.3 | 12° | SW → SW |
| November | Below 10° in darkness | — | 0° | — |
| December | Below 10° in darkness | — | -19° | — |
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: 6 Bortle 6 — Bright suburban sky. The Milky Way is only visible near the zenith; the sky glows grey-orange in photos. Modeled zenith brightness ≈ 19.02 mag/arcsec². Aurora needs roughly Kp 7.5+ to show low on the northern horizon here.
Weather & best season
Long-term NASA satellite data for this area show September as the clearest month (about 42% average cloud cover) and February as the cloudiest (65%). 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 | 71 | 77 | 82 | 88 | 96 | 109 | 109 | 107 | 103 | 94 | 81 | 72 |
| Low °F | -9 | -11 | 4 | 20 | 33 | 47 | 53 | 49 | 37 | 25 | 10 | -9 |
| Precip. (in) | 2.3 | 2.6 | 3.6 | 4.7 | 4.9 | 4.2 | 3.9 | 3.7 | 3.4 | 3.5 | 3.2 | 2.6 |
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 state park
- Ask rangers about photography permits for commercial work, models or drones.
- Weekday mornings are the least crowded at popular viewpoints.
- Trail maps often mark overlooks — combine them with the sun azimuth to plan.
- Day-use fees or passes are common; buy them online before arriving.
- Tell someone where you're going in remote areas and carry the ten essentials.
Season: Spring wildflowers and autumn color are peak seasons in most parks.
Suggested gear: Versatile zoom lens, Tripod, Park pass. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Permits, drones & access
National Park Service rules. Under federal law (54 U.S.C. 100905), still photography in National Park Service areas needs a permit only when it (1) takes place where members of the public are not allowed, (2) uses models, sets or props that are not part of the location's natural or cultural resources or administrative facilities, or (3) would cause the park to incur additional administrative costs to monitor the activity. Ordinary visitor and most landscape photography needs no permit. Commercial filming rules are separate and have changed in recent years — confirm current requirements with the park before a paid shoot.
Drones: Launching, landing or operating unmanned aircraft (drones) is prohibited in National Park Service units under a 2014 Superintendent's closure (36 CFR 1.5), except where a park has issued specific written approval. Flying from outside the boundary over park land can also violate park rules and disturb wildlife.
Nearby photo spots
Other locations within 40 km of Cahokia, closest first.
State Park
Lake
Natural Arch
State Park
Waterfall
Botanical Garden
Botanical Garden
Botanical Garden
Ghost TownFAQ
When is the best time to photograph Cahokia?
What time is golden hour at Cahokia?
Where does the sun rise and set at Cahokia?
Can you see the Milky Way from Cahokia?
Do you need a permit to photograph at Cahokia?
How far is Cahokia from Fairmont City?
Sources
Location data: Wikidata, Wikipedia. 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.