How Survivora builds your emergency plan
Updated
Survivora is a free emergency preparedness planner that turns FEMA's risk ratings for your county into a household checklist. It uses FEMA's ratings of 18 natural hazards for 3,232 counties, maps 33,503 ZIP codes to those counties, and applies published guidance from FEMA, the American Red Cross, the CDC and the EPA to calculate what you need.
Where do the risk ratings come from?
Risk ratings come from the FEMA National Risk Index, December 2025 release. The index rates every US county and county equivalent from very low to very high for 18 natural hazards, including hurricanes, wildfire, earthquakes, riverine and coastal flooding, tornadoes, winter weather and heat waves.
Your ZIP code is matched to a county using the Census Bureau's 2020 relationship file. When a ZIP code crosses county lines, Survivora uses the county that covers most of its land area. ZIP codes without a Census area, such as PO boxes, use the nearest ZIP code in the same area, and the plan says so.
How do ratings become a plan?
Any hazard rated moderate (3 of 5) or higher adds its own checklist section and action steps. Your top risks are the five highest-rated hazards that change what a household should stock or do. Drought, hail, lightning and avalanche are shown in the full ratings but don't add kit items.
FEMA's ratings measure expected losses, so counties with many people and buildings rate higher across the board. FEMA also defines a cold wave relative to local normal temperatures, which rates Miami-Dade County very high. Survivora only counts extreme cold where FEMA also rates winter storms or ice storms at relatively low or higher.
How are quantities calculated?
Every quantity scales with the people, pets and number of days you choose (3, 7 or 14).
| Item | Rule | Source |
|---|---|---|
| Drinking water | 1 gallon per person per day, plus pets | Ready.gov |
| Pet water | About 0.5 gallon per dog, 0.1 per cat, 0.05 per small animal, per day | Survivora estimate |
| Food | Non-perishable food for each person (except babies) for every day planned | Ready.gov |
| Prescription medications | At least a 7-day supply, or the full plan length if longer | Survivora estimate |
| N95 masks (wildfire or volcano risk) | 1 per person per day | Survivora estimate |
| Diapers | About 8 per baby per day | Survivora estimate |
| Flashlights and whistles | 1 per person, babies excluded | Survivora estimate |
| Water disinfection | 8 drops of unscented 6% household bleach per gallon | EPA |
| Generator safety | Run outdoors, at least 20 feet from windows and doors | CDC |
What are the limits?
County ratings are averages, so risk on your street can be higher or lower than your county's. The plan gives general preparedness information, not professional, medical or legal advice. In an emergency, follow instructions from local officials.