Historical Archive
Complete historical record of geomagnetic activity for 2023, including daily Kp Index measurements, A-Index values, and comprehensive space weather summaries from NOAA archives.
Solar Cycle 25 peak phase with maximum aurora viewing opportunities in Alaska. Peak phase of Solar Cycle 25.
Extreme activity level for 2023. Exceptional aurora activity with extreme geomagnetic storms. Prime viewing conditions in Alaska.
This archive includes daily Kp Index measurements, comprehensive geomagnetic activity records, and space weather summaries throughout 2023.
4 days of consecutive peak activity (Kp ≥ 5) from May 9, 2023 to May 12, 2023.
2023 metrics
Each card highlights a mission-critical statistic for aurora planning.
9
Highest NOAA-rated disturbance, recorded during May super storms.
Extreme
Sustained G4-G5 storming delivered all-season aurora visibility.
39 days
Days with Kp ≥ 5 classified as geomagnetic storm-level events.
4 days
May 9–12 delivered four consecutive Kp ≥ 5 monitoring alerts.
365 files
Full year coverage from NOAA SWPC daily feeds.
99.2%
Missing readings automatically flagged; NOAA backfills completed.
All cards sourced from NOAA Space Weather Prediction Center archives.
Interactive chart showing daily Kp Index throughout 2023, normalized to day-of-year (Jan 1 - Dec 31)
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Kp Index measures geomagnetic activity on a scale of 0-9, normalized to day-of-year (Jan 1 - Dec 31). Values of 5 or higher indicate geomagnetic storms with increased aurora visibility potential in Alaska.
Explore detailed geomagnetic activity, solar data, and space weather events from NOAA archives. All data converted from original NOAA formats to structured JSON.
A-Index values provide daily summaries of geomagnetic activity. Higher values (typically 30+) correlate with stronger aurora displays.
Planetary A-Index: Global geomagnetic activity summary. Mid-Latitude A-Index: Activity at mid-latitudes. High-Latitude A-Index: Activity at high latitudes (Alaska region).
Shows 8 K-index measurements per day (3-hour intervals: 00:00, 03:00, 06:00, 09:00, 12:00, 15:00, 18:00, 21:00 UTC). Provides detailed view of geomagnetic activity throughout each day. Zoom: Mouse wheel or pinch to zoom. Pan: Hold Shift and drag. Reset: Click Reset Zoom button.
Solar activity measurements including radio flux, sunspot numbers, and flare counts throughout 2023.
Daily counts of C-class (minor), M-class (moderate), and X-class (major) solar flares.
Significant space weather events, solar flares, and aurora activity reports from NOAA archives.
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Other converted data types available for 2023 (1996-2023 for most types).
Geomagnetic Event Observation Archive - Detailed event observations.
Status: ✅ Available (1996-2023)
Solar Geophysical Activity Summary - Comprehensive daily summaries.
Status: ✅ Available (1996-2023)
Solar Region Summary - Active solar region tracking.
Status: ✅ Available (1996-2023)
Daily Proton Data - Proton flux measurements.
Status: ⚠️ Available (1996-2020)
Significant geomagnetic storms and aurora activity highlights for 2023
Extreme geomagnetic storm
Exceptional aurora displays possible across Alaska
Extreme geomagnetic storm
Exceptional aurora displays possible across Alaska
Extreme geomagnetic storm
Exceptional aurora displays possible across Alaska
Extreme geomagnetic storm
Exceptional aurora displays possible across Alaska
Extreme geomagnetic storm
Exceptional aurora displays possible across Alaska
Best Aurora Viewing Months: May, October, September. These months showed the highest average geomagnetic activity, providing optimal conditions for Northern Lights viewing in Alaska.
Daily summaries generated from DGD, DSD, and RSGA reports for 2023.
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All data has been converted from original NOAA formats (DGD, DSD, RSGA) to structured JSON format for easy access and visualization.
Regionally Summarized Geomagnetic Activity (RSGA) - Daily Kp Index data
Path: json-by-year/kp-index/2023/kp-index-2023.json
Status: ✅ Converted and available (1966-2025)
DGD (Daily Geomagnetic Data): Converted for 1996-2023. Includes Planetary A-Index, Mid-Latitude A-Index, and 3-hour Kp values.
DSD (Daily Solar Data): Converted for 1996-2023. Daily solar activity measurements and indices.
Other Types: Events, GEOA, SGAS, and SRS are also converted for 1996-2023. DPD is available for 1996-2020.
Understanding where the Kp Index measurements come from and how they are calculated.
The Kp Index is a planetary-scale geomagnetic index that provides a standardized measure of global geomagnetic activity. Unlike regional indices that measure activity at specific locations, the Kp Index represents the overall geomagnetic disturbance across the entire planet.
This index is not hemisphere-specific—it combines measurements from observatories in both the Northern and Southern Hemispheres to create a unified global assessment of geomagnetic conditions.
The Kp Index is calculated using data from 13 geomagnetic observatories strategically located around the world. These observatories are positioned between 44° and 60° geomagnetic latitude in both hemispheres, providing comprehensive coverage of global geomagnetic activity.
Each observatory measures local K-index values (0-9 scale) every 3 hours. These individual measurements are then mathematically combined and normalized to produce the planetary Kp Index, ensuring consistent global representation regardless of local variations.
The Kp Index data displayed on this page is derived from RSGA (Regionally Summarized Geomagnetic Activity) reports published by NOAA's Space Weather Prediction Center.
Data Coverage:
json-by-year/kp-index/2023/kp-index-2023.jsonThe Kp Index calculation process:
This method ensures that the Kp Index represents global geomagnetic conditions rather than regional variations, making it the standard index for space weather forecasting and aurora prediction worldwide.
Note: While this dataset includes regional geomagnetic data from Northern Hemisphere observatories (such as Fredericksburg, VA and College, AK) in the DGD files for years 1996-2023, the Kp Index itself is always a global/planetary measurement that cannot be separated by hemisphere.
The Kp Index ranges from 0 (quiet) to 9 (extreme). Values of 5 or higher indicate geomagnetic storms with increased aurora visibility potential in Alaska.
Daily A-Index values summarize geomagnetic activity. Higher values (typically 30+) correlate with stronger aurora displays and extended viewing opportunities.
Geomagnetic activity varies throughout the year, with increased aurora frequency during equinox periods (March-April and September-October) in Alaska.
Original Data Source: All historical geomagnetic data displayed on this page
was originally obtained from the
NOAA Space Weather Prediction Center FTP Space Warehouse
(ftp.swpc.noaa.gov/pub/warehouse).
Data Conversion: We have extracted, processed, and converted the original NOAA data files into structured JSON format. RSGA (Kp Index) is fully converted for 1966-2025. DGD and DSD are converted for 1996-2023. Other types (Events, GEOA, SGAS, SRS) are converted for 1996-2023. DPD is available for 1996-2020. All converted data is hosted on our GitHub repository.
Future Hosting: The converted JSON datasets will be hosted on our GitHub repository in the future, providing easy access to processed historical geomagnetic data for researchers and developers.
Note: You can access the original raw data files directly from the NOAA FTP Space Warehouse using any FTP client. However, our JSON format provides a more convenient structure for web-based applications and data visualization.