New Hampshire · 6 towns compared
Northern lights in New Hampshire: tonight’s chance
New Hampshire is a narrow state with a long north-south reach: the North Country needs a smaller storm than the Merrimack valley.
Tonight at Berlin, NH
…
Reading the SWPC Kp forecast and the cloud forecast…
| Kp forecast during the dark hours | not yet forecast |
|---|---|
| Kp needed here | 6.6 (G2 moderate) |
| Cloud cover in the dark hours | loading |
| Dark sky (Sun 18° down) | 7:40 PM to 5:22 AM EDT |
| Moon | 12% lit |
| Right now, OVATION (30 to 90 min) | loading or unavailable |
| Magnetic latitude (AACGM) | 52.1° |
Hour by hour, EDT
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
Rules checked · Built by Radif Partners · How the answer works
- Kp to see it from Berlin
- 6.6
- Storm level needed
- G2 (Moderate)
- Kp for aurora overhead
- 7.0
- Most clear dark hours
- September
In New Hampshire the northern lights need a moderate to strong geomagnetic storm. In the AACGM model, Berlin, the main town of the North Country, lies at 52.1 degrees magnetic latitude and needs a planetary Kp of about 6.6; Lebanon, on the Connecticut River, about 6.7; Concord 6.8; Manchester 6.9; and Nashua, near the Massachusetts line, 6.9. The north of the state, beyond the White Mountains, is forest and lakes with very few lights, and that is where a storm night is worth driving to. In Berlin the NASA POWER cloud amount ranges from 56% in September to 78% in December, and the months with the most clear dark hours are September, February and October. The tool opens on Berlin; type your own town or a ZIP code.
North of the notches
The White Mountains divide New Hampshire in two. South of them lies the populated Lakes Region and the Merrimack valley; north of them, past the notches that the roads squeeze through, lies the North Country, a land of forest, paper-mill towns and lakes that runs to the Canadian border. Berlin, on the Androscoggin River, needs about Kp 6.6; farther north, around the Connecticut Lakes, the threshold falls slightly and the darkness deepens. On a storm night this is the part of the state where the aurora has its best chance against a black horizon.
What Kp does this town need?
Kp to see aurora from here
6.6
| Magnetic latitude (AACGM) | 52.1° |
| Kp for aurora overhead | 7.0 |
| Storm level | G2 Moderate |
| How often that level comes | about 360 days per 11-year cycle |
View line: the more southern of the SWPC oval rule and the NOAA G scale latitudes at each Kp.
Mountains: help and hindrance
The mountains offer altitude and dark valleys, but their slopes also close the horizon. An aurora at the edge of a town's range sits within a few degrees of the northern skyline, and from a valley floor in the White Mountains that skyline is a ridge. Summits and high open areas with a northern view, and lakes such as those of the North Country, are better choices than the bottoms of the notches. Weather on the high peaks is severe and changes fast in every season, which makes a lake or a field the safer bet at night.
The Connecticut valley
Along the western border, the Connecticut River valley runs north from Lebanon and Hanover toward the Vermont line and the Connecticut Lakes. Its towns are small, and the river corridor offers a few open stretches with views up the valley. Lebanon needs about Kp 6.7, between the North Country and the south of the state. Fog collects in the valley on calm autumn nights; on those nights the hilltops above it often stand in clear air under a dark sky.
The southern tier
From Concord south, the thresholds climb past Kp 6.8, a G3 storm, and the light of the Merrimack valley and of greater Boston fills the southern sky. On a strong storm the aurora can still show low in the north from a dark field, but the drive north toward the Lakes Region is usually worth it. The Vermont page and the Maine page cover the neighboring states, and the Boston page the city to the south.
Kp needed across New Hampshire
| Town | Magnetic latitude | Kp to see it | Kp overhead | Storm level |
|---|---|---|---|---|
| Berlin | 52.1° | 6.6 | 7.0 | G2 (Moderate) |
| Lebanon | 51.4° | 6.7 | 7.3 | G3 (Strong) |
| Concord | 50.9° | 6.8 | 7.5 | G3 (Strong) |
| Manchester | 50.6° | 6.9 | 7.7 | G3 (Strong) |
| Portsmouth | 50.6° | 6.9 | 7.7 | G3 (Strong) |
| Nashua | 50.4° | 6.9 | 7.8 | G3 (Strong) |
Darkness and clouds by month in Berlin
| Month | Dark hours | Dark sky, 15th | Mean cloud | Clear dark hours |
|---|---|---|---|---|
| January | 11.3 h | 6:14 PM to 5:34 AM | 74% | 3.0 h |
| February | 10.2 h | 6:51 PM to 5:06 AM | 70% | 3.0 h |
| March | 8.8 h | 8:28 PM to 5:18 AM | 67% | 3.0 h |
| April | 7.0 h | 9:16 PM to 4:13 AM | 69% | 2.2 h |
| May | 5.0 h | 10:12 PM to 3:09 AM | 69% | 1.5 h |
| June | 3.5 h | 10:59 PM to 2:31 AM | 67% | 1.1 h |
| July | 4.2 h | 10:44 PM to 2:58 AM | 62% | 1.6 h |
| August | 6.2 h | 9:43 PM to 3:56 AM | 59% | 2.6 h |
| September | 8.2 h | 8:35 PM to 4:45 AM | 56% | 3.6 h |
| October | 9.8 h | 7:37 PM to 5:24 AM | 69% | 3.0 h |
| November | 11.0 h | 5:58 PM to 5:01 AM | 74% | 2.9 h |
| December | 11.6 h | 5:51 PM to 5:29 AM | 78% | 2.6 h |