Ketchikan Gateway Borough
Population 13,549 (2025) 4,857 sq mi
Property owners in Ketchikan Gateway Borough have filed 11 federal flood insurance claims since 1978, 9th most of 30 counties in Alaska.
Hazard fingerprint Each spoke is this county’s percentile among U.S. counties where that hazard occurs. How it is computed
At a glance
The record for Ketchikan Gateway Borough in eight numbers. Each links to its section below.
Tornadoes
No tornado is recorded here in the Storm Prediction Center database, which begins in 1950.
Hurricanes and tropical storms
No tropical storm or hurricane has tracked within 100 miles since records began in 1851.
Wildfire and smoke
No large wildfire has been mapped here since satellite mapping began in 1984.
Smoke overhead
Smokiest year
2023: 15 days
Heavy smoke on 4 days in 2019, the most of any year.
Last 10 years
4.7 days a year
Medium or heavy smoke, 2016 to 2025.
2025
2 days
Medium or heavy smoke. 4 so far in 2026.
- A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.
NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.
Floods and flood insurance
11 federal flood insurance claims since 1980, with $129,000 paid.
Claims by ZIP code
| 99901 | 11 | $129,000 |
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.
River crests
Most severe crest
January 21, 2015
Lower Ketchikan Lake above Ketchikan Lake Dam near Ketchikan, 350.20 ft
1.20 feet above the 349.0 ft flood stage; moderate flooding by today’s categories.
Most recent moderate or major crest
December 5, 2020
Lower Ketchikan Lake above Ketchikan Lake Dam near Ketchikan, 350.10 ft
Moderate flooding.
River gauges
| Carlanna Lake above Carlanna Lake Dam near Ketchikan | 524.0 | 522.81 ft | 0 |
| Fish Creek near Ketchikan | 4.5 | 5.19 ft | 0 |
| Ketchikan Creek at Ketchikan Powerhouse near Ketchikan | 63.5 | 64.29 ft | 0 |
| Lower Ketchikan Lake above Ketchikan Lake Dam near Ketchikan | 349.0 | 350.20 ft | 0 |
| Tongass Narrows Tide Gauge at Ketchikan (MLLW datum) | 21.0 | — | 0 |
| Ward Creek above Lake Connell Dam near Ketchikan | 252.0 | 253.00 ft | 0 |
- Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.
NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.
Drought
NOAA’s county drought index covers the lower 48 states only.
Earthquakes, volcanoes, tsunamis and landslides
2 earthquakes of magnitude 4 or more within 50 miles since 1900; the largest was magnitude 4.3 in 2013.
5
Magnitude 2.5+ inside the county since 1973
10
Magnitude 3+ within 50 miles since 1973
2
Magnitude 4+ within 50 miles since 1900
0
Magnitude 5+ within 50 miles since 1900
Largest within 50 miles
April 29, 2013
Magnitude 4.3
60 km ENE of Thoms Place, Alaska; 5.5 miles away, 8.3 miles deep.
Most recent, magnitude 3 or more
October 9, 2022
Magnitude 3.8
61 km ESE of Metlakatla, Alaska; inside the county.
Every earthquake of magnitude 4 or more within 50 miles
| Apr 29, 2013 | 4.3 | 5.5 |
| Sep 6, 2004 | 4.2 | 29.3 |
- Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
- Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).
USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.
Tsunamis
Highest water recorded
Mar 28, 1964
2.0 ft, Ketchikan, AK
From Prince William Sound, AK (magnitude 9.2 earthquake).
On record
7 tsunamis
Since 1927.
| Oct 28, 2012 | British Columbia, M7.7 | 0.2 | 0 |
| Mar 11, 2011 | Honshu Island, M9.1 | 0.4 | 0 |
| Feb 27, 2010 | Central Chile, M8.8 | 0.2 | 0 |
| Mar 28, 1964 | Prince William Sound, AK, M9.2 | 2.0 | 0 |
| May 22, 1960 | Southern Chile, M9.5 | 0.2 | 0 |
| Aug 22, 1949 | British Columbia, M8.1 | 2.0 | 0 |
| Oct 24, 1927 | Se. Alaska, AK, M7.1 | — | 0 |
- Places where NOAA's Global Historical Tsunami Database records a tsunami's water arriving, with the greatest height it reached above sea level at the time. Only tsunamis NOAA rates probable or definite are counted. Heights from eyewitness accounts and tide gauges are mixed, and older events are less completely recorded.
NOAA NCEI/WDS Global Historical Tsunami Database, retrieved October 30, 2026.
Volcanoes within 100 miles
| Behm Canal-Rudyerd Bay | 0.6 | Very low |
| Tlevak Strait-Suemez Island | 49.5 | Very low |
| Duncan Canal | 57.4 | Very low |
- U.S. volcanoes within 100 miles, from the USGS Volcano Hazards Program. The threat category is the USGS 2018 National Volcanic Threat Assessment, which ranks volcanoes by how hazardous their past eruptions were and how many people and how much infrastructure lie near them. It is not a forecast of eruption.
USGS Volcano Hazards Program, retrieved October 30, 2026.
Mapped landslides
8,360
Landslides mapped, probable or better
177
With a recorded date
3
Source inventories
Mapped by USDA-FS AK Tongass (8,281), AK DOT (77), NASA (2).
- Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.
USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.
Severe weather and other events
22 events in the National Weather Service record, 22 of them since 1996.
0
Hail reports, 1 inch or larger
0
Hail, 2 inches or larger
0
Damaging gusts, 58 mph+
5
Winter weather events since 1996
0
Heat events since 1996
0
Cold events since 1996
- Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.
NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.
Weather records
From Ketchikan Airport, 1.9 miles from the county’s population centre, with records from 1910.
- All-time high
- 96°FJun 25, 1913
- All-time low
- −7°FJan 23, 1916
- Warmest night
- 69°FJul 30, 2009
- Coldest day
- 5°FJan 29, 1947
- Wettest day
- 8.71 inOct 11, 1977
- Snowiest day
- 31.0 inFeb 6, 1911
- Hottest year
- 1958mean 48.8°F
- Coldest year
- 1917mean 42.4°F
- Wettest year
- 2005196.03 in
- Driest year
- 199588.37 in
- Snowiest season
- 82.4 in1975-76
Median first snow
November 28
Earliest: October 18, 1930
Median last snow
March 21
Latest: May 12, 1964
0 of 28 winters had no measurable snow.
Station Ketchikan Airport (USW00025325), 84 ft elevation, 1.9 miles from the population centre. Daily records from 1910 to October 26, 2026; 99.5% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.
NOAA NCEI Global Historical Climatology Network Daily.
Federal disaster declarations
3 since 1953. The most recent: Landslides, November 13, 2024.
| Nov 13, 2024 | Mud/Landslide | DR-4846-AK |
| Apr 9, 2020 | Biological | DR-4533-AK |
| Mar 13, 2020 | Biological | EM-3446-AK |
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.
How this compares
Where Ketchikan Gateway Borough stands among 30 counties in Alaska and 3,143 in the United States.
| Tornadoes since 1950 | 0 | — |
| Tornadoes rated F3/EF3 or stronger | 0 | — |
| Tropical cyclones within 50 mi | 0 | — |
| Hurricane-strength passes within 50 mi | 0 | — |
| Wildfire acres since 1984 | 0 | — |
| Flood insurance claims | 11 | 9 / 30 |
| Flood insurance paid | $129,000 | 9 / 30 |
| Disaster declarations | 3 | 16 / 30 |
| Flood events since 1996 | 0 | — |
| Hail and wind events since 1996 | 17 | 9 / 30 |
| Winter storm events since 1996 | 5 | 21 / 30 |
| Reported damage since 1996 | $0 | — |
| River crests at major flood stage | 0 | — |
| High tide flooding days a year, last 10 years | 0.0 | — |
| Months in severe drought since 1895 | 0 | — |
| Medium or heavy smoke days a year, last 10 years | 4.7 | 13 / 30 |
| Earthquakes M4+ within 50 mi since 1900 | 2 | 28 / 30 |
| Earthquakes M2.5+ in the county since 1973 | 5 | 26 / 30 |
Neighbouring counties
| Prince of Wales-Hyder Census Area | 0 | 0 |
| Wrangell City and Borough | 0 | 0 |
Sources and vintage
Every number on this page comes from these public records.
- Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
- Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
- Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
- Storm events NOAA NCEI Storm Events Database, through 2026.
- Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
- Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
- Weather records NOAA NCEI Global Historical Climatology Network Daily, station USW00025325.
- River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
- Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
- Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
- Tsunamis NOAA NCEI/WDS Global Historical Tsunami Database.
- Volcanoes USGS Volcano Hazards Program, U.S. volcanoes and 2018 threat assessment.
- Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
- Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.
Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.