US Hailstorms Map: 70 Years of Hail Events by Size and Location

This interactive map displays over 400,000 recorded hailstorm events across the United States from 1955 to 2024, using data from NOAA’s Storm Prediction Center (SPC). Each point represents a reported hail event, colored and sized by hail diameter in inches. Filter by minimum hail size or time period to explore patterns in severe hail activity across the country.

Explore US Hailstorms

Use the size and era filters above the map to focus on the events most relevant to you. Click any point for the date, state, hail size, and damage details.

How to Use This Map

Getting Started

The map loads with egg-sized hail (2″+) and above shown by default — a threshold commonly associated with property damage. Larger circles in darker red indicate bigger hailstones. Zoom in to any region to see individual events more clearly.

Size Filter

Use the Min Size buttons to change the minimum hail diameter shown. Selecting “All” loads every report in the dataset including pea-sized hail, which significantly increases the number of points. For the most impactful events, use the 2.75″+ (baseball) or 4″+ (softball) filters.

Era Filter

Use the Era buttons to focus on a specific decade. Note that reporting coverage improved substantially after 2000 as storm spotter networks expanded, so pre-2000 data is less complete than recent years.

Share This View

The URL updates automatically as you pan and zoom, so you can copy and share any specific view from your browser address bar.

What Is Hail?

Hail is a form of solid precipitation that forms inside strong thunderstorm updrafts. Supercooled water droplets freeze onto a hailstone as it circulates within a storm, growing until it is heavy enough to fall. Hailstone size depends on the strength of the updraft — stronger updrafts keep hailstones aloft longer, allowing them to grow larger.

The National Weather Service defines severe hail as 1 inch (quarter-size) or larger. Hail causes billions of dollars in damage to crops, vehicles, rooftops, and aircraft each year in the US.

Hail Size Reference

The SPC database records hail size in inches. Common reference points used by storm spotters and the NWS:

• 0.75″ — Pea size (minimum reportable)
• 1.00″ — Quarter size (NWS severe threshold)
• 1.50″ — Ping pong ball size
• 1.75″ — Golf ball size
• 2.00″ — Egg size
• 2.75″ — Baseball size
• 4.00″ — Softball size (extreme)

Where Does Hail Occur Most in the US?

The highest concentration of large hail events occurs in a region known as Hail Alley, centered on the eastern slopes of the Rocky Mountains across Colorado, Wyoming, Kansas, Nebraska, and Oklahoma. The intersection of cold Rocky Mountain air, warm Gulf moisture, and strong wind shear in this corridor creates ideal conditions for supercell thunderstorms capable of producing very large hail.

Texas, Kansas, and Oklahoma consistently rank among the top states for both total hail events and large-hail events. The Midwest and Southeast also see significant hail activity during spring severe weather outbreaks.

Data Sources and Limitations

This map uses NOAA Storm Prediction Center (SPC) hail report data from 1955 to 2024, accessed via an Esri feature service. The dataset contains over 400,000 individual hail reports. Each record represents a single storm report, which may be one of several reports from the same storm system.

Reporting coverage is uneven over time. Early decades (1955-1980) reflect a smaller network of storm spotters and fewer automated observation systems. Modern data (2000 onwards) benefits from expanded spotter networks, social media reporting, and improved NWS verification processes. Comparisons of total event counts across eras should account for this reporting bias.

Property and crop loss figures in the dataset are in millions of dollars and reflect contemporary estimates at the time of the event, not inflation-adjusted values.

For more information, visit NOAA Severe Weather 101: Hail.

Frequently Asked Questions

What states get the most hail?

Texas, Kansas, Nebraska, Oklahoma, and Colorado consistently see the highest number of significant hail events. Wyoming and South Dakota also rank highly for large hail relative to their population and land area. This region — sometimes called Hail Alley — sits in the prime zone for supercell thunderstorm development.

When is hail season in the US?

The peak of the US hail season runs from April through June, coinciding with the spring severe weather season. The central Plains see the earliest significant hail events, often in March and April, while the northern Plains and upper Midwest peak in June and July. Hail can occur year-round in the southern states.

What is the largest hailstone ever recorded in the US?

The largest hailstone on record in the US fell in Vivian, South Dakota on July 23, 2010. It measured 8 inches in diameter and weighed nearly 2 pounds. The previous record was held by a hailstone from Aurora, Nebraska in 2003.

How does hail damage property?

Quarter-sized hail (1″) and above can dent vehicle panels and damage roofing materials. Golf ball-sized hail (1.75″) causes significant roof and vehicle damage. Baseball-sized hail (2.75″) and above can break windows, destroy crops, and be dangerous to people and animals caught in the open. Hail is estimated to cause $10-15 billion in property damage in the US annually.

What is the NOAA Storm Prediction Center?

The NOAA Storm Prediction Center (SPC) is a federal agency responsible for issuing severe thunderstorm and tornado watches across the contiguous US. The SPC maintains historical databases of tornadoes, large hail, and damaging wind events going back to 1950, which form the basis of this dataset.