Interactive tool · FEMA + NOAA data
Historical Disaster Activity Index
Compare any U.S. state or county on a disclosed 0–100 historical-activity index. State scores use FEMA declarations and NOAA event and damage history; county scores use FEMA declaration frequency, density, Major Disaster share, and declared-hazard diversity. See our methodology.
St. Mary Parish, Louisiana result
St. Mary Parish, Louisiana has a very high PlainHazard historical-activity score of 79/100, based on 49 FEMA declarations and 8 declared hazard types. It summarizes recorded activity; it is not a forecast or a FEMA risk rating.
- 79/100
- very high historical activity
- 49
- FEMA disaster declarations on record
- 8
- declared hazard types in the score
The disclosed county formula and every factor are shown directly below.
St. Mary Parish, Louisiana
Very High historical activity
St. Mary Parish, Louisiana has very high historical activity on PlainHazard's disclosed factors. This is not a forecast or a FEMA risk rating.
View full county profileThis is PlainHazard's own derived historical-activity index, not FEMA's National Risk Index and not directly comparable to the FEMA score shown below. County results use FEMA declaration measures because this database does not contain county-level NOAA damage. For evacuation planning, insurance decisions, or other personal safety decisions, consult local emergency management, the National Weather Service, or FEMA directly.
Score Breakdown
49 OpenFEMA declarations, full ingest window (2.4x national county average)
49 declarations (1.2x state county average of 41)
27 of 49 declarations are major disasters (55%)
8 different disaster types declared in St. Mary Parish
Recorded evidence
The signals behind this score
Each number is a disclosed historical input. It describes the record, not a forecast of future danger.
- FEMA declarations
- 49
- Major disasters
- 27
- Hazard types
- 8
- Flood insurance claims
- 2,532
FEMA National Risk Index
St. Mary Parish hazard risk profile
FEMA's NRI models all 64 counties in Louisiana across 18 natural hazards, weighting expected annual loss, social vulnerability, and community resilience.
Overall rating
Relatively Moderate
Rank in Louisiana
14th of 64
1 = highest risk
Expected annual loss
$60.7M
all hazards combined
Population at risk
49,313
residents modeled
Highest-risk hazards for St. Mary Parish
FEMA models 18 hazard types. Risk score = national percentile (100 = highest risk nationally). Expected annual loss is FEMA's modeled dollar figure, not a prediction.
| Hazard | Rating | Risk score | Exp. annual loss |
|---|---|---|---|
| Hurricane | Relatively High | 97.3 | $38.8M |
| Coastal Flooding | Relatively High | 93.0 | $6.5M |
| Drought | Relatively High | 91.1 | $1.4M |
| Tornado | Relatively Moderate | 86.4 | $4.4M |
| Cold Wave | Relatively Moderate | 76.7 | $2.3M |
| Heat Wave | Relatively Low | 74.9 | $897.9K |
| Lightning | Relatively Moderate | 66.7 | $343.1K |
| Riverine Flooding | Relatively Low | 50.1 | $5.3M |
Nearest-risk counties in Louisiana
Counties with the most similar FEMA NRI risk score within the same state.
| County | State rank | Rating | Risk score |
|---|---|---|---|
| St. Mary Parish (you) | 14th | Relatively Moderate | 88.9 |
| Lafourche | 12th | Relatively Moderate | 91.3 |
| Iberia | 13th | Relatively Moderate | 90.6 |
| Acadia | 15th | Relatively Moderate | 88.6 |
| St. Landry | 16th | Relatively Moderate | 88.2 |
Peers selected by closest NRI risk score in Louisiana. View St. Mary Parish's full profile for the complete hazard timeline.
Source: FEMA National Risk Index (NRI). Risk scores are national percentiles (0-100); 100 = highest risk nationally for that hazard. Expected annual loss is FEMA's modeled estimate from historical hazard frequency, exposed assets, and community resilience, not a prediction or insurance figure.
Top Disaster Types in St. Mary Parish
| Disaster Type | Declarations | Share |
|---|---|---|
| Hurricane | 30 | 61.2% |
| Flood | 7 | 14.3% |
| Coastal Storm | 4 | 8.2% |
| Other | 2 | 4.1% |
| Severe Ice Storm | 2 | 4.1% |
| Biological | 2 | 4.1% |
| Winter Storm | 1 | 2.0% |
| Severe Storm | 1 | 2.0% |
Frequently Asked Questions
How is the historical-activity score calculated?
The state score combines FEMA declaration frequency (30 points), NOAA storm-event frequency (25), NOAA property and crop damage (25), and declared-hazard diversity (20). County rows do not contain county-level NOAA damage in this database, so the county score instead uses FEMA declaration frequency (30), declaration density versus the state county average (25), Major Disaster share (25), and declared-hazard diversity (20). PlainHazard labels both as derived historical indexes, not FEMA National Risk Index scores.
What data sources are used?
The calculator uses FEMA OpenFEMA declaration records (1953–2026) for state and county scores. State scores also use NOAA Storm Events records (2015–2025); county scores do not because this database has no county-level NOAA damage. FEMA and NOAA publish the source records; the weighted score is PlainHazard-derived.
What does the historical-activity band mean?
Low (0-24), Moderate (25-49), High (50-74), and Very High (75-100) compare the recorded factors used by this tool. They describe relative historical activity, not future hazard probability, a FEMA risk rating, or a safety forecast.
Can I compare historical activity for a specific county?
Yes. Select a state first, then optionally select a county to see its historical declaration record and FEMA National Risk Index context. PlainHazard scores use FEMA declarations for that county compared with national and state averages.
How often is the data updated?
The underlying database includes FEMA declarations through 2026 and NOAA storm events through 2025. PlainHazard scores reflect the historical record available from each source and do not predict future events.
How to use this
This score is a historical-data summary, not a prediction, use it as a starting point for further research, not a final verdict on any one place.
- Score your state first to set a national baseline, then narrow to a specific county for localized detail. Browse states
- A low county score does not guarantee low risk, rare but severe hazards (a single major hurricane or earthquake) can score low on this 2015-2025 window while still posing real long-run exposure.
- FEMA's National Risk Index, official local hazard maps, and current emergency guidance are separate sources; this retrospective index contains none of their real-time or predictive signals. Read the methodology
This historical-activity score is PlainHazard's own derived index, weighted and combined from federal source data. It is not FEMA's National Risk Index or an official government rating.
Data sources: FEMA OpenFEMA Disaster Declarations (1953–2026), NOAA Storm Events Database, NFIP Flood Insurance Claims. Historical-activity scores are computed by PlainHazard and do not predict future events. This tool is for informational purposes only.
PlainHazard calculates this historical-activity score from federal source data covering 3,266 U.S. counties and county equivalents in this database, refreshed as of 2026-08-03. FEMA does not publish or endorse this score. Read our methodology for how the score is computed.
Every figure on PlainHazard is rendered directly from FEMA federal disaster data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or national statistics report, the data & editorial changelog, or report a data error.