Knox County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Knox County: 0.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Every storm within 100 miles

1. Tropical storms and hurricanes (34 kt or more, still tropical) at closest approach. Post-tropical remnants with gale-force winds are listed but not counted. Direct: track within 50 miles; near: within 100 miles. Distance is measured to the county boundary for counties and to the city centre for cities, using positions interpolated hourly between HURDAT2 fixes.

National Hurricane Center HURDAT2, 1851 to 2025.

Smoke overhead

1. 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.

Claims by ZIP code

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

The National Weather Service sets flood stages for 1 gauge here but lists no crests for it.

River gauges

1. 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.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. 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).
2. 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.

Mapped landslides

Mapped by ME GS (2).

1. 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.

More event types since 1996

Costliest events since 1996

1. Jan 10, 2024Coastal Flood, Knox$7.0 million
   National Weather Service narrative

   An intense and rapidly deepening area of low pressure over the Great Lakes region (975 mb) combined with modestly high astronomical tides to produce the third highest storm tide ever in Portland (records 1912-present). Further up the Maine coast the storm surge was slightly higher and aligned better with the high tide cycle leading to the all time highest water level reading at Bar Harbor with a water level of 15.49 feet MLLW. A new gauge in Belfast also recorded a water level of 16.38 feet MLLW. In terms of erosion the damage became worst along the Mid-Coast, significant splash-over occurred along the coast, especially in vulnerable southeast facing beaches and necks. Large…

2. Jan 13, 2024Coastal Flood, Knox$5.0 million
   National Weather Service narrative

   The astronomical tide in Portland was 11.2 feet (MLLW) at 1205 pm. Flood stage is 12 feet (MLLW). The gale to storm force onshore winds produced a storm surge of 3.37 feet in Portland Harbor. The resulting storm tide topped out at 14.57 feet (MLLW) in the Forest City with the tide remaining above flood stage for two hours and 38 minutes.||The storm created significant damage to waterfront areas of Knox County due to both inundation flooding and over wash from large coastal swells that overtopped dunes and seawalls. Flooding was up to one foot deep in businesses around Camden Harbor with significant flooding of the Camden Yacht Club where roads were closed due to flooding up to one…

3. Jan 5, 1998Ice Storm, Knox$3.0 million
   National Weather Service narrative

   A severe ICE STORM hit sections of central and southern Maine from January 5 through January 9. One of the hardest hit areas stretched from Bridgton to Lewiston to Augusta to Waterville where ice accreted several inches thick on trees, power lines, and other exposed surfaces causing almost everyone in those areas to lose electrical service. Statewide, the storm knocked out power to about 365,000 customers, an estimated 840,000 people or about 70 percent of the state's population of 1.2 million people. About one third of those that lost power were without electricity for more than a week. For some, the electricity was off for up to 3 weeks. During this time, residents and those…

4. Jan 10, 2024Coastal Flood, Knox$2.0 million
   National Weather Service narrative

   An intense and rapidly deepening area of low pressure over the Great Lakes region (975 mb) combined with modestly high astronomical tides to produce the third highest storm tide ever in Portland (records 1912-present). Further up the Maine coast the storm surge was slightly higher and aligned better with the high tide cycle leading to the all time highest water level reading at Bar Harbor with a water level of 15.49 feet MLLW. A new gauge in Belfast also recorded a water level of 16.38 feet MLLW. In terms of erosion the damage became worst along the Mid-Coast, significant splash-over occurred along the coast, especially in vulnerable southeast facing beaches and necks. Large…

5. Oct 31, 2021Flood$1.5 million
   National Weather Service narrative

   Heavy rain with reports up to 6.5 inches fell in a short period of time lead to excessive run-off with numerous roads closed and damaged due to flooding in Knox County. The towns that were hardest hit included Appleton, Camden, Hope, Rockland, Rockport and Thomaston.

6. Apr 16, 2007Flood$800,000
   National Weather Service narrative

   An area of low pressure over the southeastern United States on the morning of Sunday, April 15th, rapidly intensified as it slowly moved north to near New York City by the morning of Monday, April 16th. This intense low in combination with high pressure over eastern Canada produced Overview: An area of low pressure intensified rapidly as it moved slowly from the southeastern United States on the morning of Sunday, April 15th to near New York City by the morning of Monday, April 16th. The intense low over New York City in combination with high pressure over eastern Canada produced a very intense pressure gradient across the area which caused strong east to northeast winds to…

7. May 1, 2023Flood$690,000
   National Weather Service narrative

   Widespread and numerous flooded roads across Knox County. Coastal flooding was concurrent with the heavy rainfall and increased the impacts. Roads that were flooded include Route 1 in Camden, Route 105 in Hope and Washington, Route 126 in Jefferson, and Route 131 near Campground Road in Appleton.

8. Apr 16, 1996Debris Flow, Knox$570,000
   National Weather Service narrative

   The combination of saturated soil conditions, abnormally high tides and wave action contributed to a landslump in a coastal area of Rockland very early on the 16th. Two houses that were located on top of a seaside embankment were destroyed and sections of a highly traveled road and the public utilities that were buried beneath it were also damaged or destroyed.

9. Dec 23, 2022Coastal Flood, Knox$500,000
   National Weather Service narrative

   The morning of December 23rd had perfect alignment of a very high astronomical tide, peak storm surge of 2+ feet and large battering nearshore waves of 15 to 20 feet all coinciding at high tide. The astronomical tide in Portland was 11.3 feet MLLW at 10:16 am, already close to the established 12 foot MLLW minor flood level. The intense onshore winds produced a storm surge of 2.41 feet in Portland Harbor. The resulting storm tide topped out at 13.72 feet MLLW, it���s fourth highest water level in modern history for the Forest City (records 1912-present). The tide remained above flood stage for 195 minutes (945 am - 100 pm). A temporary new tide gauge installed by the Gulf of…

10. Apr 16, 2007Coastal Flood, Knox$500,000
    National Weather Service narrative

    High astronomical tides combined with strong northeast winds and large battering waves to produce severe coastal flooding across most of the Maine coast. It was the seventh highest tide ever recorded in Portland Harbor in modern day history (13.28 feet). The Fort Point tide gage reached 12.15 feet. Many roads were closed and residents evacuated. Damage to marinas, buoys, docks and coastal property was significant. Channel markers went adrift from their 20,000 pound blocks, causing navigation problems for mariners. The Portland Large Navigational buoy was heavily damaged while measuring 32 foot waves and was later found drifting near the Isles of Shoals. Water and waves were over…

1. 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.

All-time high

96°F2 times, most recently Jun 25, 2025

All-time low

−25°FDec 26, 1980

Warmest night

74°F4 times, most recently Jul 3, 2026

Coldest day

−5°FJan 3, 2014

Wettest day

6.35 inSep 25, 1994

Snowiest day

19.0 inJan 30, 1990

Hottest year

2024mean 48.6°F

Coldest year

1986mean 42.0°F

Wettest year

200977.11 in

Driest year

200134.19 in

Station W Rockport 1 Nnw (USC00179593), 361 ft elevation, 4.2 miles from the population centre. Daily records from 1976 to October 27, 2026; 94.4% 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.

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.

Neighbouring counties

• 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 USC00179593.
• 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.
• 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.