Tonight in Porto Alegre: Aurora is unlikely in Porto Alegre right now. Current Kp is 5.3, below the local Kp 9+ threshold. AuroraMe watches Kp, clouds and darkness for this location and sends a free alert when the next viewing window opens.
aurora visibility now
Unlikely
Kp 5.3 (Good), this spot needs Kp 9+
Kp now 5.3 Too low need 9+
Clouds 100% Overcast
Sky Dark visibility
Weather data by Open-Meteo.com Licensed under CC BY 4.0. Modified by AuroraMe: location snapped to a privacy-preserving 0.25° grid and values rounded for display.
Get a 72-hour aurora forecast and free alerts for Porto Alegre
Forecast
Time
Kp
Visibility
08.11, Today
21:00
4.7
Unlikely
22:00
4.7
Unlikely
23:00
4.7
Unlikely
00:00
5.0
Unlikely
01:00
5.0
Unlikely
02:00
5.0
Unlikely
Kp Index: 27-Day Forecast
Predicted geomagnetic activity based on solar rotation cycle.
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aurora nights per year
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Best Months to Visit Mar, Apr, Sep, Oct
Planning a trip? Find the best month and how many nights to stay
All 12 months ranked Min nights for 80% chance Push alert 1h before aurora 72-hour forecast
Why this forecast?
Five signals decide whether you'll see aurora from Porto Alegre tonight. AuroraMe re-checks them every 15 minutes, and all five have to line up: even a strong storm stays invisible behind clouds or in a bright sky.
Aurora Zone
Higher magnetic latitude = better aurora visibility. Your location's magnetic latitude determines how often auroras appear overhead.
Status Levels:
Perfect Above 62.0° — Excellent aurora visibility (daily activity)
Good 56.0° - 62.0° — Good aurora visibility (regular storms)
Acceptable 50.0° - 56.0° — Fair aurora visibility (strong storms only)
Low Below 50.0° — Poor aurora visibility (extreme storms)
Aurora Zone
Low 25.7°
Kp index
Kp measures global magnetic disturbance. Higher Kp = stronger auroras visible at lower latitudes.
Status Levels:
Storm Kp 6-9 — Geomagnetic storm, strong auroras
Active Kp 3-6 — Moderate activity, good conditions
Quiet Kp 1-3 — Low activity, weak auroras
Very Quiet Kp 0-1 — Very quiet, minimal auroras
Kp index
Active 5.3
Cloud Cover Impact
Clear skies are essential for aurora viewing. Clouds block your view of the northern lights. The percentage shows cloud coverage (0% = clear skies, 100% = overcast).
Status Levels:
Clear Clear (0-25%) — Perfect for aurora viewing
Partly Cloudy Partly Cloudy (26-50%) — May partially block view
Cloudy Cloudy (51-85%) — Significantly blocks aurora
Overcast Overcast (85%+) — Blocks aurora completely
Cloud Cover Impact
Overcast 100%
Moonlight
Bright moonlight can wash out faint auroras. New moon provides the darkest skies for optimal viewing.
Status Levels:
New Moon Darkest skies — Best for faint auroras
Crescent Dim moonlight — Good for viewing
Quarter Moderate moonlight — May wash out weak auroras
Gibbous Bright moonlight — Reduces aurora visibility
Full Moon Very bright — Only strong auroras visible
Moonlight
Crescent 14%
Darkness
Darker skies are essential for aurora viewing. The sun must be below the horizon for auroras to be visible.
Status Levels:
Night Darkest conditions — Optimal for auroras
Astronomical Twilight Dark enough — Good aurora viewing
Nautical Twilight Getting darker — Weak auroras may appear
Daylight Sun is above horizon — No aurora visible
Darkness
Astronomical Twilight
Aurora Australis Viewing in Porto Alegre
Southern city with occasional aurora australis during extreme storms.
Porto Alegre sits at 25.7° magnetic latitude, which means aurora typically becomes visible when the Kp index reaches 9+. Aurora sightings in Porto Alegre require stronger geomagnetic storms (Kp 9+), which occur a few times per year. When storms do hit, the best viewing window is 10 PM to 2 AM local time under clear, dark skies.
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Aurora is Rare in Porto Alegre — But Not Impossible
Kp 9+ needed to see aurora here
0 possible aurora nights in the next 27 days
Mar, Apr, Sep, Oct best months to visit
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Learn More About the Aurora Australis
- How to See the Northern Lights: Beginner's Guide
- Kp Index Explained: What It Means for Aurora
- Best Time to See the Northern Lights
- Geomagnetic Storms Explained: G1–G5 Scale
- Best Aurora Forecast Apps (Free & Paid)
- How Long Do the Northern Lights Last?
- How to Photograph the Northern Lights
- Aurora Australis: Southern Lights Guide
Aurora Australis in Porto Alegre: Quick Guide
How often can you see northern lights in Porto Alegre?
Based on its magnetic latitude of 25.7°, aurora viewing in Porto Alegre is extremely rare (visible only during exceptional geomagnetic storms). Actual frequency varies with the 11-year solar cycle.
Best viewing season: March to September, with peak activity during equinoxes (March and September).
What Kp index do I need to see aurora in Porto Alegre?
For Porto Alegre, you need a minimum Kp index of 9.0 for aurora to be visible. This threshold is calculated based on the city's magnetic latitude (25.7°).
Higher Kp values produce brighter, more active displays:
- Kp 9.0+: Strong, colorful displays visible even with some light pollution
Where should I look for aurora in Porto Alegre?
Watch the southern horizon for aurora during strong geomagnetic storms.
For best results, seek locations with minimal light pollution and unobstructed views of the sky. From Porto Alegre, aurora typically remains closer to the horizon, so elevated viewing locations help.
Can I see northern lights tonight in Porto Alegre?
Unlikely: Aurora unlikely tonight with Kp 5.3 (below 9.0 threshold for Porto Alegre). Enable alerts to catch future opportunities.
Check the live forecast above for the latest updates.