Solar Storm Today, December 3, 2025: G2 Geomagnetic Watch and Northern Lights Forecast for the US and Canada

Published: December 3, 2025

Overview: Why tonight matters for aurora chasers

A burst of “space weather” from the Sun is lining up with North America tonight, and it could bring the aurora borealis (northern lights) into view for millions of people across the United States and Canada.

NOAA’s Space Weather Prediction Center (SWPC) has issued a G2 (Moderate) geomagnetic storm watch for December 3–4 (UTC days) after a coronal mass ejection (CME) from an X1.9-class solar flare on December 1 was observed heading for a glancing blow to Earth. That CME is expected to arrive at roughly the same time as a burst of fast solar wind from a coronal hole, increasing the odds of geomagnetic disturbances and auroras at mid‑latitudes. ^[1]

Several independent forecasts—from NOAA, Canada’s space-weather centre, EarthSky, SpaceWeather.com, The Weather Network and multiple media outlets—are now aligned on a scenario where G2-level activity is likely, with a small chance of brief G3 (Strong) storming if everything lines up just right. ^[2]

Here’s what’s happening on the Sun, and where the northern lights are most likely to appear over the US and Canada tonight (December 3, 2025).

What’s happening on the Sun right now?

A powerful flare and a glancing CME

Early on December 1, a powerful X1.9-class solar flare erupted from an active region just rotating onto the Sun’s northeastern limb. NASA and NOAA instruments recorded a large CME blasting into space shortly after the flare. ^[3]

NOAA’s analysis indicates:

The CME was associated with the X1.9 flare at 02:49 UTC on December 1, from Region 4299.
Most of the CME’s mass is directed away from Earth, but models show the flank “grazing” our planet.
Because the exact timing and strength of the impact are uncertain, SWPC issued a G2 (Moderate) geomagnetic storm watch for December 3–4 (UTC). ^[4]

At the same time, a co-rotating interaction region (CIR) and a high-speed solar wind stream (HSS) from a coronal hole are expected to sweep past Earth today. It’s the combination of the CIR, high-speed stream and glancing CME that makes this setup particularly interesting for auroras. ^[5]

Giant sunspots and an active Solar Cycle

The flare and CME are part of a broader burst of activity from a string of huge sunspot regions now facing Earth. EarthSky and SpaceWeather.com highlight: ^[6]

A massive sunspot complex (AR4294–AR4296) that rivals the area of the famous 1859 “Carrington Event” sunspot—about 90% as large, though the current flares are much weaker.
The return of Region 4299, which produced the X1.9 flare that launched today’s CME.
At least nine active regions on the Earth-facing disk, several capable of further significant flares. ^[7]

Although NOAA’s latest sunspot statistics suggest Solar Cycle 25 is beginning to trend downward, the current disk configuration still supports episodes of intense solar activity—exactly what we’re seeing this week. ^[8]

Official space weather alerts for December 3–4

NOAA (United States)

NOAA SWPC’s key messages for today: ^[9]

G2 (Moderate) geomagnetic storm watch in effect for December 3–4 (UTC).
A glancing CME from the December 1 X1.9 flare plus a high-speed solar wind stream and CIR are expected to disturb Earth’s magnetic field.
Brief G3 (Strong) conditions are possible if the CME and CIR arrive simultaneously and the interplanetary magnetic field (IMF) turns strongly southward (Bz < 0), which greatly enhances coupling with Earth’s magnetosphere. ^[10]

SpaceWeather.com, which aggregates real-time data, reported around midday UT that: ^[11]

The planetary Kp index was at 3 (quiet)—meaning the main disturbance had not yet arrived.
The IMF’s Bz component was around –10 nT, already pointing southward, a favorable orientation for auroras once denser, faster solar wind arrives.
A new coronal hole is expected to drive elevated solar wind speeds on December 3–4.

Canada’s space-weather forecast

Natural Resources Canada issued a Magnetic Activity Review and Forecast at 12:17 UT on December 3, noting: ^[12]

Over the last 24 hours, the auroral zone saw unsettled with stormy intervals, while the sub‑auroral zone was quiet to active.
In the last 6 hours, the auroral zone reached active + stormy intervals.
For the next 6 hours, they expect unsettled to active conditions in the auroral and sub‑auroral zones.
Over the next 24 hours, the auroral zone is forecast to remain unsettled with active intervals, consistent with NOAA’s G2 watch.

This means magnetic activity across much of northern Canada is expected to be elevated through tonight, supporting aurora visibility where skies are dark and clear.

When is the best time to watch tonight?

Multiple forecasts that draw on NOAA’s 3‑day geomagnetic outlook converge on a similar timing for peak activity over North America: ^[13]

Late afternoon to early evening (roughly 4–7 p.m. EST / 21:00–00:00 UTC):
- Potential for G2 (Moderate) conditions as the main disturbance ramps up.
Evening to around midnight (7 p.m.–1 a.m. EST / 00:00–06:00 UTC):
- Activity may drop back toward G1 (Minor), but still supportive of auroras at higher latitudes.
After midnight to pre‑dawn (1–4 a.m. EST / 06:00–09:00 UTC):
- A second window where G2-level conditions could return, especially if the high‑speed stream fully engages.

In local terms:

For Eastern Canada and the U.S. Northeast, the early part of the storm (evening) is favored. ^[14]
For the Prairies and central Canada, as well as parts of the U.S. northern Plains, the late‑night and pre‑dawnwindow may be better. ^[15]

Remember that you also need astronomical darkness—so far-north locations where it gets dark early will see a longer viewing window.

Where you might see the northern lights in the United States

Core “likely” zone (based on current forecasts)

Using NOAA’s aurora maps, the SWPC watch, and today’s detailed breakdown from Space.com and other outlets, the most favored US states for aurora visibility tonight (Dec. 3–4) include: ^[16]

High chance (if skies are clear):

Alaska
Washington
Idaho
Montana
North Dakota
South Dakota
Minnesota
Wisconsin
Michigan
Maine
Vermont
New Hampshire
Wyoming
Iowa
New York

Space.com’s latest article explicitly lists these 15 states as lying on or north of the main aurora view line for tonight, based on NOAA’s current map. ^[17]

Extended “conditional” zone if the storm intensifies

If the storm briefly reaches strong G3 levels—something forecasters describe as possible but not guaranteed—auroras could push farther south. Outlets such as People.com, TS2.tech and regional coverage suggest additional states that could see a faint glow on the northern horizon if conditions over‑perform: TechStock²+2People.com+2

Oregon
Nebraska
Illinois
Indiana
Ohio
Pennsylvania
Massachusetts

Some forecasts note that, during a solid G2 storm (roughly Kp ~6), horizon-viewing of the aurora is sometimes possible as far south as the Illinois–Wisconsin border, especially from darker rural locations. ^[18]

This does not guarantee visible auroras that far south—but it does mean skywatchers in these states have more reason than usual to keep an eye on updated aurora maps tonight.

Northern lights outlook for Canada

Magnetic activity: auroral and sub‑auroral zones

Canada sits squarely under the auroral oval, and tonight’s G2 watch strongly favors the country—especially at northern latitudes—for aurora activity.

According to the Canadian government’s Zonal Review and Forecast issued today, the auroral zone has recently experienced active to stormy intervals, with the next 24 hours expected to remain unsettled with active intervals. Even the sub‑auroral zone (which covers more southerly parts of Canada) is forecast to see quiet–active levels, consistent with an elevated aurora chance. ^[19]

Regional breakdown

The Weather Network’s latest guidance for Wednesday night into Thursday morning highlights: ^[20]

Highest aurora potential (assuming clear skies):
- Northern and central Canada, including the Yukon, Northwest Territories, Nunavut, northern British Columbia, northern Alberta, northern Saskatchewan, Manitoba, and northern Quebec.
- Probability tools show especially high chances around communities like Yellowknife, Whitehorse, Rankin Inlet and Inuvik, while major southern cities such as Toronto, Ottawa and Montreal show very low or near-zero probabilities at this time. ^[21]
Good but cloud-dependent chances:
- Northwestern Ontario and southern Manitoba, especially overnight, as the core of G2 activity may align with clearing skies in some models. ^[22]
- Parts of Alberta, where a mix of clear and cloudy conditions is expected.
Atlantic Canada:
- Some forecast models suggest pockets of clearer skies over New Brunswick and Prince Edward Islandthis evening, giving residents a shot at seeing auroral glows to the north if the storm is strong enough. ^[23]

Overall, Canada’s aurora odds are strong tonight, but cloud cover will be the spoiler in many regions. Both Environment Canada and private forecasters warn that large parts of the country could be socked in by clouds associated with an early‑season winter storm, particularly in eastern regions. ^[24]

How intense could this storm get?

G2 vs G3: what the scales mean

On NOAA’s space weather scales: ^[25]

G2 (Moderate) geomagnetic storms can cause:
- Minor power-grid fluctuations at high latitudes
- Increased drag on low‑Earth‑orbit satellites
- Intermittent HF radio and navigation issues in polar regions
- Auroras that can reach mid‑latitudes, roughly corresponding to Kp ~6
G3 (Strong) storms bring more pronounced impacts:
- Corrective actions may be required for power systems
- Spacecraft operations can experience surface charging and anomalies
- Aurora can push significantly farther toward the equator (Kp ~7)

Current forecasts center on G2 as the most likely outcome, with a non‑zero chance of brief G3 intervals if the CME and high‑speed stream arrive together and the IMF turns strongly southward for several hours. ^[26]

This is not expected to match the intensity of the G4 (Severe) event in November that produced auroras as far south as Texas, but it could still deliver a memorable regional display for northern US states and much of Canada. ^[27]

Ground weather: the critical wild card

Even with perfect space weather, clouds kill aurora views.

The Weather Network notes that “much of Canada will have cloudy skies” this evening, particularly across central and eastern parts of the country, though there are pockets of clearer conditions in Atlantic Canada, northwestern Ontario, southern Manitoba and parts of Alberta at various times overnight. ^[28]
In the U.S., NOAA’s Weather Prediction Center is tracking an early December winter storm bringing snow, ice and low clouds across portions of the Appalachians, interior Northeast and Great Lakes, reducing viewing chances and making travel hazardous in some popular aurora‑chasing regions. TechStock²+1

If you plan to look for auroras, check local cloud forecasts and winter weather advisories before heading out, and avoid traveling in dangerous conditions simply to chase the lights.

Practical tips for seeing the northern lights tonight

Based on guidance from NOAA, aurora scientists and recent how‑to pieces from Space.com, TS2.tech, People.com and the Geophysical Institute: ^[29]

Go dark and look north
- Choose a location well away from city lights with a clear view toward the northern horizon (or overhead/entire sky at higher latitudes).
- In southern mid‑latitudes, auroras often appear as a faint whitish or greenish glow low in the north, sometimes with vertical rays.
Watch the timing windows
- For much of North America, late evening through pre‑dawn is favored, with specific windows around 4–7 p.m. and 1–4 a.m. Eastern flagged as most promising by NOAA‑based forecasts. ^[30]
Use real‑time tools, not just “tonight’s forecast”
- Check NOAA’s Aurora Dashboard and 30‑minute aurora forecast, which update frequently and show where the auroral oval is predicted to be in the next hour. ^[31]
- Popular apps such as My Aurora Forecast, SpaceWeatherLive, Aurora Now and others can send Kp alerts and plot the current auroral oval over a map. ^[32]
Give your eyes time to adapt
- Spend 20–30 minutes in the dark without bright screens so your night vision can fully adjust; your camera may detect auroras before your eyes do.
Photographing the aurora
- Smartphones: Use Night Mode (iPhone) or Pro/Manual Mode (many Androids), turn off flash, and hold as steady as possible—tripods help. ^[33]
- DSLR/mirrorless cameras: Use a wide‑angle lens, long exposures, and ISO settings in roughly the 1600–3200 range as a starting point, adjusting based on brightness and noise. ^[34]
Stay safe and warm
- Dress for winter conditions, especially in northern states and Canada where temperatures can plummet overnight.
- Be aware of road conditions if snow or ice is in the forecast, and don’t put yourself at risk for a photo opportunity. TechStock²+1

Bottom line

A G2 (Moderate) geomagnetic storm watch is in effect today and tomorrow (December 3–4, 2025) thanks to a glancing CME from an X1.9 flare plus an incoming high‑speed solar wind stream and CIR. ^[35]
Northern lights are likely across Alaska, most of northern and central Canada, and the northern tier of the United States from Washington to Maine, with a chance of auroras dipping farther south if the storm peaks toward G3 strength. ^[36]
Cloud cover and local weather will be critical; many areas, especially in eastern Canada and parts of the northeastern US, may have limited visibility due to an early‑season winter storm. ^[37]

If forecasts verify, tonight could deliver one of the more memorable aurora displays of late 2025 for northern parts of the US and large swaths of Canada—another reminder that even as Solar Cycle 25 begins to ease, the Sun still has plenty of surprises in store.