Hurricane Isaias
One of the tropical cyclone disasters on NOAA’s billion-dollar list: $5.8 billion in losses at 2024 prices ($4.8 billion at the time) and 16 deaths.
What the offices filed during it
The 73 most significant tropical cyclone episodes filed in these dates, colored by kind.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Losses, 2024 dollars
- $5.8 billion
- Losses at the time
- $4.8 billion
- Deaths
- 16
The losses and deaths are NCEI’s, counting everything the disaster did. The episodes below are only what the Weather Service filed in its Storm Events record, which counts damage differently and often not at all, so the two never add up and are shown apart.
By state, as filed
| State | Events | Deaths | Injuries | Damage filed |
|---|---|---|---|---|
| Connecticut | 17 | 1 | 0 | $54 million |
| Virginia | 89 | 0 | 5 | $19 million |
| New York | 61 | 7 | 1 | $19 million |
| North Carolina | 129 | 2 | 14 | $14 million |
| Maryland | 71 | 1 | 1 | $3.6 million |
| Georgia | 24 | 0 | 0 | $1.1 million |
| Massachusetts | 23 | 0 | 3 | $227,000 |
| Pennsylvania | 92 | 2 | 18 | $191,000 |
| South Carolina | 4 | 1 | 1 | $120,000 |
| New Hampshire | 15 | 1 | 0 | $55,000 |
| Wisconsin | 1 | 0 | 0 | $50,000 |
| Maine | 14 | 0 | 0 | $40,000 |
| Rhode Island | 8 | 0 | 0 | $32,000 |
| Mississippi | 4 | 0 | 0 | $31,000 |
| Florida | 28 | 0 | 0 | $15,000 |
| North Dakota | 7 | 0 | 0 | $10,000 |
| New Mexico | 1 | 0 | 0 | $10,000 |
| Indiana | 5 | 0 | 0 | $4,000 |
| Ohio | 3 | 0 | 0 | $3,000 |
| Arizona | 6 | 0 | 0 | $2,000 |
| Colorado | 61 | 0 | 1 | |
| New Jersey | 40 | 0 | 8 | |
| Delaware | 13 | 0 | 0 | |
| South Dakota | 5 | 0 | 0 | |
| Illinois | 3 | 0 | 0 | |
| Kansas | 3 | 0 | 0 | |
| Michigan | 2 | 0 | 0 | |
| Missouri | 2 | 0 | 0 | |
| District of Columbia | 1 | 0 | 0 |
Episode by episode
- Flash Flood and Hail in Mississippi, August 1 to 2, 2020A weak cold front moved across central and southern Mississippi and helped initiate a few thunderstorms by the afternoon of August 2nd. These storms moved over the same locations and produced some flash flooding.
- Tropical Storm and Tropical Depression in Florida, August 2 to 3, 2020Tropical Storm Isaias moved between Grand Bahama and Southeast Florida in the morning of August 2.
- Tropical Storm in Florida, August 2 to 4, 2020Isaias tracked offshore of the local forecast area through the day August 3rd. Occasional rainbands moved onshore over the local area through the day with gusts of 20-40 mph.
- Tropical Storm in Georgia, August 2 to 4, 2020Isaias tracked offshore of the local forecast area through the day August 3rd. Occasional rainbands moved onshore over the local area through the day with gusts of 20-40 mph.
- Flash Flooding in Pennsylvania, August 2, 2020Thunderstorms brought locally heavy rain to Berks County during the early hours of August 2. Rainfall totals as high as 4 to 6 inches fell in the county.
- Flash Flood in Michigan, August 2, 2020Many roads and interstates closed around Detroit due to flash flooding as thunderstorms produced torrential rainfall of 1.5 to 3 inches in a relatively short period.
- Tornadoes in Connecticut, August 2, 2020A strong warm front moving northeast across southern New England and an approaching short wave trough combined to produce three tornadoes in western Connecticut during the early evening hours of Sunday, August 2nd, 2020.
- Flood in Illinois, August 2, 2020Scattered thunderstorms produced heavy rain and isolated flooding during the afternoon of August 2nd.
- Tornado in Massachusetts, August 2, 2020A strong warm front moving northeast across southern New England and an approaching short wave trough combined to produce a weak tornado in western Massachusetts during the early evening hours of Sunday, August 2nd, 2020.
- Tornado in Massachusetts, August 2, 2020A strong warm front moving northeast across southern New England and an approaching short wave trough combined to produce a weak tornado in western Massachusetts during the early evening hours.
- Flash Flood and Hail in Arizona, August 2, 2020Scattered thunderstorms developed over Santa Cruz and southwest Cochise County during the afternoon and moved southwest through the evening. Storms produced heavy rain and large hail in the Elgin/Sonoita area and one storm uprooted trees at Tubac Presidio State Historic Park.
- Flash Flood in Wisconsin, August 2 to 3, 2020A slow moving cold front and upper low pressure area brought repeated thunderstorms to southern Milwaukee County during the evening. 3 to 7 inches of rainfall caused the flash flooding of streets and creeks.
- Flash Flood in Missouri, August 2 to 3, 2020A slow moving cold front triggered showers and storms through the afternoon and into the overnight hours. Some of the storms produced up to four inches of rain causing flash flooding.
- Flash Flooding and Heavy Rain in Kansas, August 3, 2020A subtle shortwave trough in northwest flow aloft helped produce early morning thunderstorms. These early morning storms were isolated but slow moving allowing for rainfall totals up to 6 inches.
- Heavy Rain in North Carolina, August 3 to 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast late Monday night, August 3rd through Tuesday morning, August 4th. The Tropical Storm produced heavy rain which caused minor flooding across portions of northeast North Carolina.
- Heavy Rain in Virginia, August 3 to 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast late Monday night, August 3rd through Tuesday morning, August 4th. The Tropical Storm produced heavy rain which caused minor flooding across portions of central and eastern Virginia.
- Flood in Michigan, August 3, 2020Heavy rain totaling slightly greater than 3 inches lead to flooding in Port Huron.
- Flash Flooding in Illinois, August 3, 2020A slow-moving frontal boundary triggered a couple bands of showers and thunderstorms across southeast Illinois from late morning through mid-afternoon of August 3rd.
- Heavy Rain in Maryland, August 3 to 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast late Monday night, August 3rd through Tuesday morning, August 4th. The Tropical Storm produced heavy rain which caused minor flooding across portions of the Lower Maryland Eastern Shore.
- Flash Flooding and Hail in Georgia, August 3, 2020Widespread thunderstorms along and ahead of a stationary front across north and central Georgia resulted in scattered severe thunderstorms with numerous reports of damaging thunderstorm winds and several reports of large hail.
- Tropical Storm in South Carolina, August 3, 2020Isaias first developed as a tropical storm on July 29, 2020 south of Puerto Rico before tracking west-northwest and first making landfall on the Dominican Republic.
- Flooding and Lightning Strike in Indiana, August 3, 2020During the afternoon and evening hours of August 3rd, widespread thunderstorms moved over much of Indiana. One of these thunderstorms damaged a large tree via a lightning strike. The 1 to 3 inches of rain caused brief flooding, but only limited impacts were noted.
- Flooding and Damaging Wind in Ohio, August 3, 2020Showers and thunderstorms developed ahead of a cold front moving through the region.
- Flash Flood in Missouri, August 3, 2020Scattered slow-moving thunderstorms during the afternoon produced heavy rainfall. Hourly totals of one to two inches resulted in isolated flooding. The storms were associated with an upper-level disturbance moving eastward across the mid Mississippi Valley.
- Flooding in Indiana, August 3, 2020Showers and thunderstorms developed ahead of a cold front moving through the region.
- Flash Flooding and Debris Flow in Colorado, August 3, 2020Strong to severe storms developed over the higher terrain and along the I-25 corridor during the afternoon and evening hours.
- Tornadoes and Storm Surge in North Carolina, August 3, 2020Hurricane Isaias came off the African coast as a tropical wave on July 23, 2020. It became Tropical Storm Isaias on July 30th, further strengthening to a hurricane on the 31st. After crossing the Bahamas, it weakened to a tropical storm.
- Tornado and Storm Surge in South Carolina, August 3 to 4, 2020Hurricane Isaias came off the African coast as a tropical wave on July 23, 2020. It became Tropical Storm Isaias on July 30th, further strengthening to a hurricane on the 31st. After crossing the Bahamas, it weakened to a tropical storm.
- Tornadoes and Tropical Storm in North Carolina, August 3 to 4, 2020Hurricane Isaias originated from a vigorous tropical wave off the coast of Africa that was first identified by the National Hurricane Center on July 23, 2020. The tropical wave gradually became more organized, and became Tropical Storm Isaias on July 30.
- Tropical Storm and Flash Flooding in North Carolina, August 3 to 4, 2020Hurricane Isaias made landfall in southeast North Carolina, then moved north through coastal North Carolina.
- Flash Flood and Flood in Florida, August 3 to 4, 2020Several low level boundaries were across the local forecast area including a wake trough axis post-Isaias across south Georgia and an outflow boundary stalled near the I-95 corridor of NE FL.
- Coastal Flood in North Carolina, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Coastal Flood in Virginia, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Tornadoes in North Carolina, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Tropical Storm in North Carolina, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Tornadoes in Virginia, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Tropical Storm in Virginia, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Tropical Storm in Maryland, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Tornadoes in Maryland, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Tornadoes and Tropical Storm in Maryland, August 4 to 5, 2020Tropical Storm Isaias moved up the east coast, passing through southern Maryland on the morning of Tuesday, August 4th, 2020, spawning several tornadoes as well as flooding rain and tropical storm force winds.
- Tropical Storm and Flooding in Virginia, August 4, 2020Tropical Storm Isaias moved up the east coast, passing through southern Maryland on the morning of Tuesday, August 4th, 2020, spawning several tornadoes as well as flooding rain and tropical storm force winds.
- Tornadoes and Tropical Storm in Pennsylvania, August 4, 2020Tropical Storm Isaias brought high winds, heavy rain, several tornadoes, and coastal flooding to the mid-Atlantic region, becoming the most impactful tropical cyclone to impact most of the region since Sandy in 2012.
- Flash Flood in Virginia, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast late Monday night, August 3rd through Tuesday morning, August 4th. The Tropical Storm produced heavy rain which caused flash flooding across portions of central Virginia.
- Tornadoes and Tropical Storm in Delaware, August 4, 2020Tropical Storm Isaias brought high winds, heavy rain, several tornadoes, and coastal flooding to the mid-Atlantic region, becoming the most impactful tropical cyclone to impact most of the region since Sandy in 2012.
- Tornado and Tropical Storm in Maryland, August 4, 2020Tropical Storm Isaias brought high winds, heavy rain, several tornadoes, and coastal flooding to the mid-Atlantic region, becoming the most impactful tropical cyclone to impact most of the region since Sandy in 2012.
- Flood in District of Columbia, August 4, 2020Tropical Storm Isaias moved up the east coast, passing through southern Maryland on the morning of Tuesday, August 4th, 2020, spawning several tornadoes as well as flooding rain and tropical storm force winds.
- Tornadoes and Tropical Storm in New Jersey, August 4, 2020Tropical Storm Isaias brought high winds, heavy rain, several tornadoes, and coastal flooding to the mid-Atlantic region, becoming the most impactful tropical cyclone to impact most of the region since Sandy in 2012.
- Coastal Flood in Maryland, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Coastal Flood in Virginia, August 4, 2020The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th.
- Flash Flood and Damaging Wind in Pennsylvania, August 4, 2020Tropical Storm Isaias tracked from south to north across far eastern Pennsylvania during the morning and early afternoon of August 4, 2020. Heavy rain impacted the Susquehanna Valley, and there was one report of a tree down on a home in Lancaster County.
- Tropical Storm in New York, August 4, 2020Category 1 Hurricane Isaias with maximum sustained winds of 85 mph, made landfall near Ocean Isle Beach, NC at 11:10 pm on August 3rd. Isaias' intensity weakened back to Tropical Storm strength as its forward speed increased to near 30 mph early morning of August 4th.
- Tropical Storm in New Jersey, August 4, 2020Category 1 Hurricane Isaias with maximum sustained winds of 85 mph, made landfall near Ocean Isle Beach, NC at 11:10 pm on August 3rd. Isaias intensity weakened back to Tropical Storm strength as it forward speed increased to near 30 mph early morning of August 4th.
- Tropical Storm in Connecticut, August 4, 2020Tropical Storm Isaias tracked northeast from the eastern Carolinas across the mid-Hudson Valley and into New England. The center of the storm passed close to Albany, NY on August 4th.
- Tropical Storm in Connecticut, August 4, 2020Category 1 Hurricane Isaias with maximum sustained winds of 85 mph, made landfall near Ocean Isle Beach, NC at 11:10 pm on August 3rd. Isaias' intensity weakened back to Tropical Storm strength as its forward speed increased to near 30 mph during the early morning of August 4th.
- Tropical Storm and Astronomical Low Tide in New Hampshire, August 4 to 5, 2020Tropical Storm Isaias was the first tropical storm to impact New Hampshire since 2011. The center of the storm tracked west of the state, keeping the flooding rain associated with the storm across New York.
- Tropical Storm in Maine, August 4 to 5, 2020Tropical Storm Isaias was the first tropical storm to impact Maine since 2011. The center of the storm tracked well west of the state, keeping all the heavy rain associated with the storm across New York.
- Tropical Storm and Strong Wind in Massachusetts, August 4, 2020Tropical Storm Isaias tracked northeast from the eastern Carolinas across the mid-Hudson Valley and into New England. The center of the storm passed close to Albany, NY on August 4th.
- Heavy Rain in New York, August 4, 2020Tropical Storm Isaias moved north along the east coast of the United States on August 3rd and 4th, eventually moving across southeast NY state during the afternoon of August 4th and across the Champlain Valley during the evening hours.
- Tornado in Connecticut, August 4, 2020A tornado was spawned and briefly touched down in Westport as Tropical Storm Isaias impacted Southern Connecticut.
- Tropical Storm in Massachusetts, August 4, 2020Tropical Storm Isaias moved from coastal Virginia eastern New York state, near the Connecticut/Massachusetts border on Tuesday, August 4. As the storm reached the New York City area, southerly winds were maximizing across southern New England, causing widespread wind damage.
- Flash Flooding in Pennsylvania, August 4, 2020Rain and embedded thunderstorms moved through Northeast Pennsylvania on the 4th associated with Tropical Storm Isaias. Widespread rainfall of 3 to 5 inches occurred across the region. Locally heavy rainfall produced areas of flash flooding.
- Flash Flooding and High Wind in New York, August 4, 2020Tropical Storm Isaias tracked northeast from the eastern Carolinas across the mid-Hudson Valley and into New England. The center of the storm passed close to Albany on August 4th. This storm brought high winds and heavy rain to the region through the period.
- Flood in New Jersey, August 4, 2020Tropical Storm Isaias moved northward along the East Coast, passing west of New York City during the afternoon. With a tropical airmass in place, heavy rainfall on the leading edge of the storm resulted in isolated flash flooding in parts of northeast New Jersey.
- Tropical Storm in Connecticut, August 4, 2020Tropical Storm Isaias moved from coastal Virginia eastern New York state, near the Connecticut/Massachusetts border on Tuesday, August 4. As the storm reached the New York City area, southerly winds were maximizing across southern New England, causing widespread wind damage.
- Flash Flood in New York, August 4, 2020Rain and embedded thunderstorms moved through south Central and Eastern New York on the 4th associated with Tropical Storm Isaias. Widespread rainfall affected the area with locally heavy downpours causing isolated flash flooding in Sullivan county.
- Tropical Storm in Rhode Island, August 4, 2020Tropical Storm Isaias moved from coastal Virginia eastern New York state, near the Connecticut/Massachusetts border on Tuesday, August 4. As the storm reached the New York City area, southerly winds were maximizing across southern New England, causing widespread wind damage.
- Tornado and Hail in Colorado, August 4, 2020Severe thunderstorms produced large hail, from quarter to tennis ball size over Adams, Lincoln and Weld counties. The hail damaged trees and property, including multiple vehicles. One tornado touched down briefly in open country.
- Tornadoes and Hail in South Dakota, August 4, 2020A thunderstorm became severe as it moved into Tripp County. The storm produced large hail, strong wind gusts, and two tornadoes.
- Tornado and Hail in North Dakota, August 4, 2020A strong short wave trough approaching the area combined with a surface trough to produce thunderstorms over western North Dakota. A couple of storms became severe over northwest North Dakota in an area of ample low level moisture and deep layer shear.
- Flash Flood in New Mexico, August 5, 2020A backdoor cold front that moved into eastern New Mexico recharged moisture over the region on August 5, 2020. Thunderstorm coverage increased over the area however most activity was light across the western half of the state.
- Flash Flooding and Debris Flow in Colorado, August 5, 2020Isolated showers and storms developed over the mountains and high valleys during the day. Thunderstorm development then shifted to the I-25 corridor in the afternoon, specifically the Pikes Peak region, where multiple storms produced large hail.
- Flood in Florida, August 5, 2020Sufficient tropical moisture across South Florida in the wake of Isaias and ample daytime heating allowed for scattered thunderstorms to develop across the east coast metro as the Gulf Coast sea Breeze collided with the semi-pinned Atlantic sea Breeze.
- Flash Flooding in Virginia, August 5, 2020Scattered thunderstorms along a frontal boundary produced heavy rain which caused flash flooding across portions of central and south central Virginia.
More
Every billion-dollar disasterEvery storm of 2020The 2020 hurricane seasonTornadoes in 2020
Sources
NOAA NCEI, U.S. Billion-Dollar Weather and Climate Disasters (2025), https://doi.org/10.25921/stkw-7w73, and the Storm Events Database for the episodes.