Best time to see the northern lights in Wyoming

Wyoming gets under one clear night a year — 0.8 in a typical year at Sheridan, its strongest of 5 tracked locations. Only an extreme storm brings the aurora within reach: aurora needs Kp 7 or higher, which the planetary index last reached on 21 January 2026. The threshold rises to Kp 8 at the southern end of the state, against Kp 7 at Sheridan. November carries the most of that thin history, at 0.15 clear nights in a typical year, which is not a month worth booking.

These are typical-year figures: a 1996–2026 planetary Kp record crossed with a 2001–2020 cloud normal. They describe a normal year, not tonight — the live Sheridan forecast shows the actual cloud, moon and darkness right now. Check tonight's forecast for Sheridan →

🌌 Clear nights a year

0.8

Storm nights only — Under one clear aurora night a year: 0.8 clear nights in a typical year.

🌟 Best month

November

0.15 clear nights in a typical year — a storm night, not a season

⚡ Kp needed

Kp 7–8

Horizon threshold across the state; last reached 21 January 2026

📍 Strongest location

Sheridan

Aurora on 0.8 clear nights a year, against 0.2 at the weakest of 5 tracked locations

Month by month in Wyoming

Astronomical darkness, the nights on which planetary Kp reached Kp 7–8 inside that darkness, the same count over the current solar cycle alone, and what the local cloud normal leaves of the long-run figure.

Month	Astronomical darkness	Opportunity nights	Since 2023	Mean cloud	Clear opportunity nights	Moon-free
January	11.25h	0.16	0.54	65.2%	0.06	53.2%
February	10.25h	0	0	67.3%	0	53%
March	8.73h	0.1	0.27	65.3%	0.03	53.5%
April	6.85h	0.23	0.27	64.5%	0.08	55.3%
May	4.8h	0.13	0.54	63.9%	0.05	53.8%
June	3.54h	0.03	0	50.9%	0.01	51.5%
July	4.26h	0.03	0	40.4%	0.02	54.1%
August	6.24h	0.2	0.27	43.5%	0.11	55.4%
September	8.18h	0.23	0.54	44%	0.13	56.5%
October	9.83h	0.33	0.54	56.4%	0.14	54.9%
November	11.05h	0.36	0.54	59.7%	0.15	55%
December	11.59h	0.03	0	65.1%	0.01	55.1%

Opportunity nights are the whole 1996–2026 record. In the current solar cycle alone (since 2023), November has averaged 0.54 rather than 0.36.

November: 11.05h of astronomical darkness a night
November: 0.36 nights reach the Kp threshold inside that darkness
November: 59.7% mean cloud leaves 0.15 of them clear
November: 55% of those nights are moon-free

Every tracked location in Wyoming

All 5 of them, strongest first. The month column is each location's own best month, not the state's.

Location	Clear nights a year	Best month	Kp needed	Magnetic latitude
Sheridan	0.8	November	Kp 7	52.2°
Cody	0.7	September	Kp 7	51.7°
Cheyenne	0.3	November	Kp 8	48.8°
Casper	0.2	November	Kp 8	50.4°
Jackson	0.2	November	Kp 8	50.5°

How these numbers were made

Evaluated at: Sheridan, 44.7972° N 106.9562° W — darkness and cloud are properties of that point, not of a region.
Darkness: sun geometric altitude at or below -18 degrees (astronomical twilight). 10-minute samples across every year of the Kp record (1996-2026), averaged per night of each month rather than sampled on one representative day.
Geomagnetic record: GFZ Potsdam planetary Kp index, 3-hourly, 1996-01-01 to 2026-09-07 — 89,661 intervals, licensed CC BY 4.0.
Cloud: NASA POWER SYN1DEG 20-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2020), parameter CLOUD_AMT. A monthly mean, not a forecast.
Moon: A night counts as moon-free below 35% lunar illumination while the moon is up.
Auroral oval: NOAA auroral oval — model estimate, reported separately. The figure for this location is above, beside the measured record it never replaces.
Clear opportunity nights: clear opportunity nights = nights on which at least one 3-hour Kp interval falls inside local astronomical darkness and reaches the location’s horizon threshold, scaled by (1 - monthly mean cloud amount)
Dataset version: Version 2026-09-07, computed offline by seo-ops scripts/aurora-usa-best-time-data.ts.

The same dataset for every tracked city and state is published at US Aurora Season Climatology, and how the live forecast is built is on the methodology page. Kp record: GFZ Potsdam (CC BY 4.0). Cloud normal: NASA POWER.

Frequently asked questions

When can you see the northern lights in Wyoming?

There is no season for it. Wyoming averages 0.8 clear nights of aurora a year across the 1996–2026 Kp record, so the answer is whenever an extreme storm happens to fall on a dark, clear night. November holds the most of that history, at 0.15 clear nights in a typical year. Watch the live forecast rather than the calendar.

What Kp is needed to see the aurora from Wyoming?

Wyoming needs Kp 7 or higher for aurora on the northern horizon, Kp 8 for a noticeable display and Kp 9 for a bright one. Across the state that horizon threshold runs from Kp 7 in the north to Kp 8 in the south. The NOAA auroral-oval model puts the edge of the oval about 50.4° above the northern horizon at Wyoming at Kp 7. That is a model estimate, separate from the measured Kp record.

Has the aurora ever been visible from Wyoming?

Yes. In the 1996–2026 planetary Kp record the index reached the horizon threshold for Wyoming, Kp 7, most recently on 21 January 2026, and the Kp 8 needed for a noticeable display on 12 November 2025. Whether anyone saw it also depended on the cloud, moonlight and darkness of that night, which the Kp record does not carry.