Montgomery County, Pennsylvania
County storm and disaster record · FIPS 42091 · population 856,020 · 483 sq mi
NOAA's Storm Events Database holds 1,973 records for Montgomery County, Pennsylvania from 1950 through June 30, 2026, on 1,111 days; the most frequent are severe thunderstorm wind events (634 records). NOAA records 284 flood or flash floods there since 1996, with 15 deaths; its 6,200 flood insurance claims since 1978 (OpenFEMA) rank 79th of 2,942 U.S. counties; the deadliest named storm on its flood record is Hurricane Floyd (1999). The deadliest single record is the July 27, 1994 tornado: 3 deaths, 25 injuries and $99.5 million in damage in 2025 dollars. FEMA has issued 29 declarations naming the county since 1965, 27 of them for natural hazards; the latest for a natural hazard was “Remnants of Hurricane Ida” on September 10, 2021.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 1,973on 1,111 days, 1950 to June 30, 2026
- Deaths recorded
- 74143 injuries
- Damage, 2025 dollars
- $405Mas filed (scale steps before 1993)
- Tornadoes
- 19strongest F3
- FEMA declarations
- 29latest 2021
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Montgomery County most?
The most frequent records are severe thunderstorm wind events: 634 since 1956. 47% of its severe thunderstorm wind events since 1956 fell in June and July. The rank column places the county among Pennsylvania's counties by days with a record per 1,000 square miles of land over each hazard's complete period.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 634 | 278 | 1956-2026 | 4 | 11 | $4.5M | 6 of 67 |
| Winter storms | 378 | 281 | 1996-2026 | 10 | 58 | $14M | 7 of 67 |
| Floods | 284 | 183 | 1996-2026 | 15 | 8 | $244M | 3 of 67 |
| High wind and dust storms | 141 | 127 | 1996-2025 | 4 | 13 | $19M | 6 of 67 |
| Hail | 132 | 77 | 1957-2025 | 0 | 0 | – | 5 of 67 |
| Heat | 117 | 103 | 1996-2025 | 31 | 6 | $13K | 3 of 67 |
| Fog, smoke and funnel clouds | 73 | 56 | 1999-2026 | 0 | 0 | – | 4 of 67 |
| Drought | 49 | 49 | 1997-2010 | 0 | 0 | – | 6 of 67 |
| Lightning | 48 | 36 | 1996-2023 | 0 | 3 | $4.5M | 5 of 67 |
| Extreme cold | 46 | 34 | 1996-2022 | 6 | 0 | – | 7 of 67 |
| Heavy rain | 44 | 42 | 1996-2017 | 0 | 0 | – | 5 of 67 |
| Tornadoes | 19 | 18 | 1956-2021 | 4 | 41 | $119M | 7 of 67 |
| Hurricanes and tropical storms | 4 | 3 | 2008-2020 | 0 | 0 | $131K | 5 of 67 |
| Wildfires | 3 | 3 | 2002-2015 | 0 | 3 | $1K | 9 of 67 |
| Rip currents and high surf | 1 | 1 | 2019-2019 | 0 | 0 | – | 4 of 67 |
Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.
How many tornadoes has Montgomery County had?
NOAA records 19 tornadoes in Montgomery County from 1956 to 2021, the strongest rated F3, with 4 deaths and 41 injuries recorded in the county. That is 7th of 67 Pennsylvania counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.
Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 20 tornadoes whose track touched Montgomery County since 1950 (NOAA's county records number 19: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 4 people.
| Date | Tornado | Rating | Path | Killed |
|---|---|---|---|---|
| 1994-07-27 21:52, as SPC files it | Royersford | F3 | 2 mi | 3 |
| 2021-09-01 15:35, as SPC files it | Ambler | EF2 | 8.28 mi | 1 |
Map of the strongest tornado tracks in Pennsylvania.
Every tornado record filed for Montgomery County (19)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2021-09-01 | Flourtown, Montgomery County | EF2 8.28 mi x 400 yd | 1 | 2 | $5.4M |
| 2021-08-18 | Elroy, Montgomery County | EF1 2.03 mi x 140 yd | 0 | 0 | – |
| 2020-11-30 | Montgomeryville Airport, Montgomery County | EF0 0.87 mi x 100 yd | 0 | 0 | – |
| 2020-08-04 | Hartranft, Montgomery County | EF0 3.14 mi x 200 yd | 0 | 0 | – |
| 2003-09-23 | Narberth, Montgomery County | F1 0.8 mi x 100 yd | 0 | 0 | $1.6M |
| 1995-05-29 | Norristown To, Montgomery County | F1 1.5 mi x 50 yd | 0 | 0 | – |
| 1994-08-14 | Norristown, Montgomery County | F1 1 mi x 100 yd | 0 | 0 | – |
| 1994-07-27 | Montgomery County | F3 2 mi x 100 yd | 3 | 25 | $100M |
| 1991-08-03 | Montgomery County | F1 3 mi x 100 yd | 0 | 0 | $2.5M step |
| 1989-11-16 | Montgomery County | F0 0.2 mi x 50 yd | 0 | 0 | $25K step |
| 1989-11-16 | Montgomery County | F1 1.5 mi x 50 yd | 0 | 3 | $250K step |
| 1988-07-26 | Montgomery County | F0 1.5 mi x 50 yd | 0 | 0 | $250K step |
| 1988-07-17 | Montgomery County | F1 1.8 mi x 67 yd | 0 | 1 | $250K step |
| 1982-05-20 | Montgomery County | F0 0.2 mi x 7 yd | 0 | 3 | $3K step |
| 1978-08-28 | Montgomery County | F1 0.5 mi x 67 yd | 0 | 1 | $25K step |
| 1966-07-04 | Montgomery County | F0 2 mi x 20 yd | 0 | 5 | $250K step |
| 1961-06-08 | Montgomery County | F2 1 mi x 200 yd | 0 | 1 | $25K step |
| 1960-06-24 | Montgomery County | F2 0.8 mi x 27 yd | 0 | 0 | $250K step |
| 1956-08-13 | Montgomery County | F2 1.3 mi x 333 yd | 0 | 0 | $25K step |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.
When was the last damaging storm in Montgomery County?
The most recent record with damage, injuries or deaths is the June 22, 2026 flash flood ($5,000 in damage in 2025 dollars).
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-28 | Dense FogMontgomery County · forecast zone Eastern Montgomery | 0 | 0 | – | |
| 2026-06-22 | Thunderstorm WindCheltenham, Montgomery County | 50 kt wind | 0 | 0 | – |
| 2026-06-22 | Thunderstorm WindMiquon, Montgomery County | 50 kt wind | 0 | 0 | – |
| 2026-06-22 | Thunderstorm WindBetzwood, Montgomery County | 50 kt wind | 0 | 0 | – |
| 2026-06-22 | Flash FloodHill Crest, Montgomery County | 0 | 0 | $5K | |
| 2026-06-06 | Thunderstorm WindPottstown, Montgomery County | 50 kt wind | 0 | 0 | – |
| 2026-06-06 | Thunderstorm WindFagleysville, Montgomery County | 50 kt wind | 0 | 0 | – |
| 2026-05-20 | Thunderstorm WindColmar, Montgomery County | 55 kt wind | 0 | 0 | – |
| 2026-05-20 | Thunderstorm WindLayfield, Montgomery County | 55 kt wind | 0 | 0 | – |
| 2026-05-20 | Thunderstorm WindLimerick Center, Montgomery County | 55 kt wind | 0 | 0 | – |
| 2026-05-20 | Thunderstorm WindPennsburg, Montgomery County | 55 kt wind | 0 | 0 | – |
| 2026-05-20 | Thunderstorm WindPottstown, Montgomery County | 55 kt wind | 0 | 0 | – |
Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.
The deadliest and costliest records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1994-07-27 | TornadoMontgomery County The parent thunderstorm that produced two tornadoes and downburst wind damage in eastern Chester County split in two near Spring City in Chester County. The left or western thunderstorm entered Montgomery County in Royersford and wind related damage intensified as the thunderstorm moved northeast through Royersford. ... | F3 2 mi x 100 yd | 3 | 25 | $100M |
| 1999-09-16 | Flash FloodCountywide, Montgomery County Hurricane Floyd battered Eastern Pennsylvania (especially Southeast sections around Philadelphia) on September 16th and brought with it torrential and in some places record breaking rains and damaging winds. The hurricane caused widespread flash flooding as storm totals averaged around six inches in the Poconos and ... | 3 | 8 | $21M | |
| 2010-07-05 | Excessive HeatMontgomery County · forecast zone Montgomery The hottest weather of the summer season occurred on July 5th through the 7th throughout Eastern Pennsylvania. Except for the Poconos, many high temperatures on the 6th and 7th exceeded 100 degrees, some places even on the 5th exceeded 100 degrees. Even in the Poconos, high temperatures approached 100 degrees on the ... | 3 | 0 | – | |
| 2002-08-01 | HeatMontgomery County · forecast zone Montgomery The excessive heat that began on July 28th continued through August 5th. The combination of high temperatures in the 90s and high dew points produced heat indices of over 100 each day through the 5th. A cold frontal passage late in the day on the 5th ended the excessive heat. The hottest day of this spell for most ... | 3 | 0 | – | |
| 1998-07-21 | HeatMontgomery County · forecast zone Montgomery A heat wave affected Southeast Pennsylvania from July 20th through the 23rd. Eleven persons died (Eight in Philadelphia and three in Montgomery County.) from the heat. They were usually discovered in homes with closed windows and inadequate ventilation. A 21-month-old Philadelphia baby was inadvertently left in a car ... | 3 | 0 | – | |
| 1996-01-19 | FloodMontgomery County · forecast zone Montgomery The combination of snowmelt from the previous week's two storms, unseasonably warm temperatures and an additional one to two inches of rain caused the flash flooding of almost every small stream and significant roadway flooding the afternoon and early evening hours on the 19th. Major flooding of the larger streams and ... | 3 | 0 | $5.9M | |
| 1999-06-07 | HeatMontgomery County · forecast zone Montgomery A large high pressure system over the southeastern United States pumped in a hot and humid air mass across most of Eastern Pennsylvania for three days. The hottest day was the 8th. A weak trough brought in slightly cooler and considerably drier air on the 9th, although high temperatures still reached around 90 ... | 2 | 1 | – | |
| 2021-09-01 | Flash FloodKing Of Prussia, Montgomery County Widespread flash flooding occurred in Montgomery County with many road closures and vehicles stranded. Numerous water rescues took place. There were two flood related fatalities, one in Skippack and one in Bridgeport. Many buildings and homes were flooded. Most waterways in the county overflowed their banks, including ... | 2 | 0 | $23M |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1994-07-27 | TornadoMontgomery County | F3 2 mi x 100 yd | 3 | 25 | $100M |
| 2001-06-16 | Flash FloodSouth Portion, Montgomery County | 1 | 0 | $56M | |
| 1996-09-08 | Flash FloodSouthern, Montgomery County | 2 | 0 | $38M | |
| 2006-06-27 | FloodCountywide, Montgomery County | 0 | 0 | $32M | |
| 2021-09-01 | Flash FloodSassamansville, Montgomery County | 0 | 0 | $23M | |
| 2021-09-01 | Flash FloodOreland, Montgomery County | 0 | 0 | $22M | |
| 1999-09-16 | Flash FloodCountywide, Montgomery County | 3 | 8 | $21M | |
| 2009-08-02 | Flash FloodNarberth, Montgomery County | 0 | 0 | $17M |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $2.5M, in the dollars of the day) holds: August 3, 1991 (tornado, Montgomery County).
Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.
Is it getting more frequent?
Records per decade for Montgomery County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 1 | 6 | 19 | 30 | 61 | 76 | 187 | 254 |
| Winter storms | – | – | – | – | 28 | 101 | 170 | 79 |
| Floods | – | – | – | – | 20 | 83 | 114 | 67 |
| High wind and dust storms | – | – | – | – | 19 | 68 | 51 | 3 |
| Hail | 1 | 1 | 6 | 4 | 14 | 33 | 31 | 42 |
| Heat | – | – | – | – | 29 | 38 | 31 | 19 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
47% of its severe thunderstorm wind events since 1956 fell in June and July. The two busiest months are in violet.
The values, month by month
Jan 202 · Feb 196 · Mar 134 · Apr 82 · May 131 · Jun 271 · Jul 314 · Aug 242 · Sep 91 · Oct 61 · Nov 106 · Dec 143 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Montgomery County
FEMA's register lists 29 declarations that include Montgomery County: 21 major disasters, 8 emergencies and 0 fire management assistance declarations. Most were for hurricane (8) and flood (7).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2021-09-10 | DR-4618 | Hurricane | Remnants of Hurricane Ida |
| 2020-03-30 | DR-4506 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3441 | Biological | Covid-19 |
| 2016-03-23 | DR-4267 | Snowstorm | Severe Winter Storm and Snowstorm |
| 2014-02-06 | EM-3367 | Severe Ice Storm | Severe Winter Storm |
| 2013-01-10 | DR-4099 | Hurricane | Hurricane Sandy |
| 2012-10-29 | EM-3356 | Hurricane | Hurricane Sandy |
| 2011-09-12 | DR-4030 | Flood | Tropical Storm Lee |
| 2011-09-08 | EM-3340 | Flood | Remnants of Tropical Storm Lee |
| 2011-09-03 | DR-4025 | Hurricane | Hurricane Irene |
| 2011-08-29 | EM-3339 | Hurricane | Hurricane Irene |
| 2010-04-16 | DR-1898 | Snowstorm | Severe Winter Storms and Snowstorms |
| 2006-06-30 | DR-1649 | Severe Storm | Severe Storms, Flooding, and Mudslides |
| 2005-09-10 | EM-3235 | Hurricane | Hurricane Katrina |
| 2004-09-19 | DR-1555 | Severe Storm | Severe Storms and Flooding Associated With Tropical Depression Frances |
| 2004-09-19 | DR-1557 | Hurricane | Tropical Depression Ivan |
| 2004-08-06 | DR-1538 | Severe Storm | Severe Storms and Flooding |
| 2003-03-14 | EM-3180 | Severe Storm | Snow |
| 2001-06-21 | DR-1383 | Severe Storm | Tropical Storm Allison |
| 1999-09-18 | DR-1294 | Hurricane | Hurricane Floyd Major Disaster Declarations |
| 1996-09-13 | DR-1138 | Flood | Flooding Associated With Tropical Depression Fran |
| 1996-01-21 | DR-1093 | Flood | Severe Storms and Flooding |
| 1996-01-13 | DR-1085 | Snowstorm | Blizzard of 96 |
| 1994-03-10 | DR-1015 | Severe Storm | Severe Winter Storms |
| 1993-03-16 | EM-3105 | Snowstorm | Severe Snowfall & Winter Storm |
| 1973-07-17 | DR-400 | Flood | Severe Storms & Flooding |
| 1972-06-23 | DR-340 | Flood | Tropical Storm Agnes |
| 1971-09-18 | DR-312 | Flood | Floods |
| 1965-08-18 | DR-206 | Drought | Water Shortage |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.
How many floods has Montgomery County had?
NOAA's Storm Events Database holds 284 flood or flash flood records for Montgomery County from 1996 to 2026, on 183 days, with 15 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Montgomery County ranks 79th of 2,942 U.S. counties. The 100 counties with the most claims
| Storm | Began | Records | Deaths in the county |
|---|---|---|---|
| Hurricane Floyd | 1999-09-16 | 1 | 3 |
| Hurricane Ida | 2021-09-01 | 3 | 2 |
| Tropical Depression Fran | 1996-09-08 | 1 | 2 |
| Hurricane Irene | 2011-08-28 | 1 | 1 |
| Tropical Storm Allison | 2001-06-16 | 1 | 1 |
The National Flood Insurance Program has paid $185 million on 6,200 claims filed in Montgomery County; the most in one year was 811 in 2011. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1978: 117 · 1979: 394 · 1980: 37 · 1981: 5 · 1982: 70 · 1983: 88 · 1984: 219 · 1985: 38 · 1986: 9 · 1987: 14 · 1988: 16 · 1989: 62 · 1990: 9 · 1991: 28 · 1992: 11 · 1993: 135 · 1994: 57 · 1995: 13 · 1996: 458 · 1997: 3 · 1998: 7 · 1999: 553 · 2000: 30 · 2001: 414 · 2002: 8 · 2003: 73 · 2004: 335 · 2005: 132 · 2006: 243 · 2007: 58 · 2008: 11 · 2009: 232 · 2010: 150 · 2011: 811 · 2012: 25 · 2013: 17 · 2014: 169 · 2015: 12 · 2016: 7 · 2017: 11 · 2018: 66 · 2019: 93 · 2020: 258 · 2021: 634 · 2022: 6 · 2023: 27 · 2024: 18 · 2025: 4 · 2026: 13.
Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.
FEMA's modeled risk for Montgomery County
FEMA's National Risk Index rates Montgomery County Relatively High overall, with an expected annual loss of $297 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Winter Weather | Very High | $3.5M | 12 a year (modeled) |
| Strong Wind | Very High | $9.6M | 7 a year (modeled) |
| Cold Wave | Relatively High | $30M | about once a year (modeled) |
| Heat Wave | Relatively High | $20M | 9.6 modeled event-days a year |
| Riverine Flooding | Relatively High | $193M | 5.7 a year (modeled) |
| Tornado | Relatively High | $15M | once in about 4 years (modeled) |
| Earthquake | Relatively Moderate | $14M | once in about 720 years (modeled) |
| Hurricane | Relatively Moderate | $8.9M | once in about 12 years (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Montgomery County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Tornadoes in PennsylvaniaEvery Pennsylvania tornado since 1950 and the counties with the most per square mile
- Severe thunderstorm wind in PennsylvaniaThe state's severe thunderstorm wind events, by county, year and month
- The Pennsylvania recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Montgomery CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Montgomery County's FEMA declarations (CSV)29 rows: every declaration that named the county, for your own analysis