Denver, CO · magnetic latitude 48.2°
Northern lights in Denver: tonight’s chance
Denver needs a strong storm, a clear night and a drive out of the Front Range glow; the first is the rare part.
Tonight at Denver, CO
…
Reading the SWPC Kp forecast and the cloud forecast…
| Kp forecast during the dark hours | not yet forecast |
|---|---|
| Kp needed here | 7.4 (G3 strong) |
| Cloud cover in the dark hours | loading |
| Dark sky (Sun 18° down) | 7:52 PM to 5:39 AM MDT |
| Moon | 13% lit |
| Right now, OVATION (30 to 90 min) | loading or unavailable |
| Magnetic latitude (AACGM) | 48.2° |
Hour by hour, MDT
7 PM
Kp –
– ☁
No
8 PM
Kp –
– ☁
No
9 PM
Kp –
– ☁
No
10 PM
Kp –
– ☁
No
11 PM
Kp –
– ☁
No
12 AM
Kp –
– ☁
No
1 AM
Kp –
– ☁
No
2 AM
Kp –
– ☁
No
3 AM
Kp –
– ☁
No
4 AM
Kp –
– ☁
No
5 AM
Kp –
– ☁
No
6 AM
Kp –
– ☁
No
Rules checked · Built by Radif Partners · How the answer works
- Kp to see it from Denver
- 7.4
- Storm level needed
- G3 (Strong)
- Kp for aurora overhead
- 8.9
- Most clear dark hours
- November
Denver needs a planetary Kp of about 7.4 to see the northern lights, a G3 (Strong) storm on the NOAA scale. The city lies at 48.2 degrees magnetic latitude in the AACGM model, south of the latitude NOAA associates with G3 and close to where G4 storms, about 100 per eleven-year solar cycle, have brought aurora. The oval itself would reach overhead only around Kp 8.9, so a Denver sighting is almost always a glow low in the north, often red. The sky is rarely the problem: Denver's NASA POWER cloud amount stays between 38% in September and 57% in February, among the lowest of the cities on this site. By clear dark hours, November, October and September lead. The tool checks each night against that threshold, hour by hour.
The Mile High City is far from the oval
Altitude does not help with the aurora: what counts is distance from the oval, and Denver, at 48.2 degrees magnetic latitude, is far from it. Its threshold of Kp 7.4 puts it among the harder cities on this site, together with Philadelphia and New York. That has a simple practical consequence. A Denver aurora night is an event, announced by an SWPC watch for a G3 or G4 storm, and worth preparing for: a plan for where to go, a clear northern horizon, and patience.
How dark, how clear: one town, one month
Hours of full darkness on the 15th
10.9 h
| Dark sky | 6:17 PM to 5:11 AM |
| Including nautical twilight | 12.0 h |
| Mean cloud amount (NASA POWER) | 48% |
| Clear dark hours on an average night | 5.6 h |
Computed for 2027; the hours move by a few minutes from one year to the next.
Escaping the light dome
The Front Range urban corridor glows from Fort Collins to Colorado Springs, and Denver sits in the middle of it. The northern horizon from the city is lit by its own suburbs. The plains to the east and northeast empty quickly: past the airport and the last subdivisions, the farmland and grassland around Prospect Valley, Keenesburg or the Pawnee Grassland give a dark northern horizon within an hour or so. On the night of a big storm, many people make the same drive, so a county road beats a popular overlook.
Red, not green
What Denver sees of a storm is usually the upper part of the aurora. Green light, the most common color, comes from heights of about 120 to 400 km according to SWPC; red light comes from above 300 km. Seen from far to the south, the green part stays below the horizon and the red part shows, sometimes as a diffuse glow that the eye barely registers and a phone camera records clearly. The colors guide lets you test the geometry with your own distances.
Timing
Big storms keep their own schedule: a G4 storm that peaks at midday Mountain time can be fading by nightfall, which is why the tool rates hours, not days.
Denver is on Mountain time, seven hours behind Universal Time in winter. Full darkness on December 15 runs from 6:13 PM to 5:36 AM. The three-night forecast converts the SWPC blocks and keeps the dark ones, and the Colorado page compares the rest of the state.
Kp needed around Denver
| Town | Magnetic latitude | Kp to see it | Kp overhead | Storm level |
|---|---|---|---|---|
| Fort Collins | 48.9° | 7.2 | 8.5 | G3 (Strong) |
| Boulder | 48.4° | 7.3 | 8.8 | G3 (Strong) |
| Denver | 48.2° | 7.4 | 8.9 | G3 (Strong) |
| Colorado Springs | 47.3° | 7.5 | beyond 9 | G3 (Strong) |
| Grand Junction | 47.0° | 7.6 | beyond 9 | G3 (Strong) |
| Pueblo | 46.8° | 7.6 | beyond 9 | G3 (Strong) |
Darkness and clouds by month in Denver
| Month | Dark hours | Dark sky, 15th | Mean cloud | Clear dark hours |
|---|---|---|---|---|
| January | 11.1 h | 6:34 PM to 5:43 AM | 56% | 4.9 h |
| February | 10.2 h | 7:06 PM to 5:20 AM | 57% | 4.4 h |
| March | 9.1 h | 8:36 PM to 5:39 AM | 55% | 4.1 h |
| April | 7.5 h | 9:14 PM to 4:44 AM | 55% | 3.4 h |
| May | 5.9 h | 9:57 PM to 3:53 AM | 56% | 2.6 h |
| June | 5.0 h | 10:31 PM to 3:28 AM | 46% | 2.7 h |
| July | 5.4 h | 10:22 PM to 3:48 AM | 47% | 2.9 h |
| August | 6.9 h | 9:36 PM to 4:31 AM | 47% | 3.7 h |
| September | 8.5 h | 8:39 PM to 5:09 AM | 38% | 5.2 h |
| October | 9.8 h | 7:49 PM to 5:40 AM | 44% | 5.5 h |
| November | 10.9 h | 6:17 PM to 5:11 AM | 48% | 5.6 h |
| December | 11.4 h | 6:13 PM to 5:36 AM | 56% | 5.0 h |