KP Threshold & Odds
Kp 8+ minimum
Magnetic latitude: 48.3°
Only during strong storms. Consider a short trip north.
aurora visibility now
Unlikely
Aurora is unlikely in St. Louis right now (0%). Check back when geomagnetic activity increases.
- Status
- Unlikely
- Probability
- 0%
- Kp Index
- 4.0
- Cloud Cover
- 1%
Tonight's Aurora Conditions
Located at 47.5° MLAT, aurora requires significant storm activity. KP 7+ events several times per year bring northern lights within view.
Rare Lower 48 (Rare) Local time 07:46
Tonight's Snapshot
- Cloud cover: 1%
- Sky darkness: Daylight
- Moon illumination: 14%
- Best window: 13:00 (Unlikely)
Viewing Tips for St. Louis
- Face north or north-east with an open horizon.
- Get 20-40 minutes away from city lights if possible.
- Coastlines, lakes, and higher ground improve visibility.
Nearby Alternatives
Higher odds to the north of St. Louis.
What affects visibility
Aurora Zone
Higher magnetic latitude = better aurora visibility. Your location's magnetic latitude determines how often auroras appear overhead.
Status Levels:
PerfectAbove 62.0° - Excellent aurora visibility (daily activity)
Good56.0° - 62.0° - Good aurora visibility (regular storms)
Acceptable50.0° - 56.0° - Fair aurora visibility (strong storms only)
LowBelow 50.0° - Poor aurora visibility (extreme storms)
Aurora Zone
Low 48.3°
Kp index
Kp measures global magnetic disturbance. Higher Kp = stronger auroras visible at lower latitudes.
Status Levels:
StormKp 6-9 - Geomagnetic storm, strong auroras
GoodKp 3-6 - Moderate activity, good conditions
LowKp 1-3 - Low activity, weak auroras
Very QuietKp 0-1 - Very quiet, minimal auroras
Kp index
Good 4
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:
ClearClear (0-25%) - Perfect for aurora viewing
Partly CloudyPartly Cloudy (26-50%) - May partially block view
CloudyCloudy (51-85%) - Significantly blocks aurora
OvercastOvercast (85%+) - Blocks aurora completely
Cloud Cover Impact
☀️ Clear
Moonlight
Bright moonlight can wash out faint auroras. New moon provides the darkest skies for optimal viewing.
Status Levels:
New MoonDarkest skies - Best for faint auroras
CrescentDim moonlight - Good for viewing
QuarterModerate moonlight - May wash out weak auroras
GibbousBright moonlight - Reduces aurora visibility
Full MoonVery 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:
NightDarkest conditions - Optimal for auroras
Astronomical TwilightDark enough - Good aurora viewing
Nautical TwilightGetting darker - Weak auroras may appear
DaylightSun is above horizon - No aurora visible
Darkness
Daylight
Forecast
Time
Kp
Visibility
09.10, Today
10:00
5.0
Unlikely
11:00
5.0
Unlikely
12:00
5.0
Unlikely
13:00
6.0
Unlikely
14:00
6.0
Unlikely
15:00
6.0
Unlikely
16:00
5.7
Unlikely
10.10, Tomorrow
19:00
4.0
Unlikely
22:00
3.7
Unlikely
01:00
3.0
Unlikely
04:00
3.0
Unlikely
07:00
1.7
Unlikely
10:00
2.3
Unlikely
13:00
2.7
Unlikely
16:00
2.7
Unlikely
11.10, Sunday
19:00
4.7
Unlikely
22:00
5.7
Unlikely
01:00
4.3
Unlikely
04:00
3.0
Unlikely
07:00
2.7
Unlikely
10:00
2.3
Unlikely
13:00
2.0
Unlikely
16:00
2.7
Unlikely
12.10, Monday
19:00
3.0
Unlikely
Monthly Trends
This calendar shows likelihood trends based on aurora activity, darkness, aurora zone, moonlight, and historical data. Clouds are excluded due to low predictability. Use it to pick promising nights, then confirm with the 72h forecast closer to date.
Past 365 Days
Aurora Nights
Premium
Local threshold
Kp ≥ 8.0
Best Season
Premium
Seasonal Pattern
This calendar shows how often aurora was observed here by week across the year. Colors reflect historical intensity: greener months had more aurora nights, grey had little or none. Use it to plan trips around the strongest months, then confirm exact nights with the 72h forecast.
Get Alerted Before Aurora Appears
Aurora alerts, cloud cover, and forecast context for your location. Check current conditions before viewing.
Smart Alerts before spikes
Short-term outlook for the next few days
Multiple locations
Trip planner: month, year
Alternative viewing locations
Compare a few locations with higher magnetic latitude, or search the full US directory.
Browse all US locations or see the Missouri forecast.
Indianapolis
Aurora reaches Indianapolis during strong geomagnetic storms at 48.8° magnetic latitude. Watch the northern horizon from a dark spot away from city lights.
CURRENT STATUS
Unlikely
View
Cedar Rapids
Aurora possible at 50.7° magnetic latitude during active periods. KP 6+ required for visibility. Strong storms can bring impressive displays.
CURRENT STATUS
Unlikely
View
Chicago
Located at 50.9° MLAT with decent aurora opportunities. Geomagnetic storms with KP 6+ can produce visible displays. Monitor forecasts for storm alerts.
CURRENT STATUS
Unlikely
View
Planning a trip? Best months across Missouri →
Learn More About Aurora Viewing
Best Time to See Aurora in Missouri
Month-by-month clear-night numbers for Missouri, and where St. Louis sits among them.
How Aurora Forecast USA WorksOur data sources, 5-factor algorithm, and update frequency explained.
Aurora Borealis ForecastLive aurora forecast overview for the entire United States.
Dark-Sky SitesTracked dark-sky locations by state, with Bortle class and drive distance.
Northern Lights in St. Louis: Quick Guide
Minimum Kp Needed
8.0+
Current Kp Index
4.0
What Kp index is needed to see aurora in St. Louis?
Use Kp 8+ as a planning threshold for St. Louis, based on its magnetic latitude. Aurora visibility also requires darkness, suitable sky conditions, and current geomagnetic activity.
Where should I look for aurora in St. Louis?
Choose a dark location with an unobstructed view of the northern horizon. Check current local conditions before travelling, because clouds and light pollution can prevent viewing.
Can I see aurora tonight in St. Louis?
Check the current forecast for St. Louis. A Kp value at or above Kp 8+ is only one condition; darkness and local cloud cover also affect whether aurora can be seen.
Traveling? Track multiple locations easily
Compare aurora chances across cities and get alerts for all your planned destinations.
For brighter shows consider Fairbanks
