- Active monitoring · 24/7/365 global coverage
Weather Alerts API
for Global Severe Weather Notifications
Global Severe Weather Monitoring
CustomWeather delivers real-time severe weather alerts for locations around the world. Developers, businesses, emergency managers, logistics providers, insurers, and travel applications use our API to receive official weather warnings, watches, advisories, and other hazardous weather notifications in JSON or XML.
Alerts are continuously monitored and updated as government meteorological agencies issue new information, allowing applications to notify users immediately when hazardous weather threatens a location.
- Live Alerts
- 247 active
- Logistics & Fleet Management
- Aviation
- Insurance
- Utilities
- Agriculture
- Construction
- Smart Cities
- Outdoor Recreation
- Travel Apps
- Energy
- Public Safety
- Emergency Management
Alert Type
Description
Hurricane Warning
Tropical cyclone impacts
Tornado Warning
Immediate tornado threat
Severe Thunderstorm Warning
Damaging winds, hail or lightning
Flash Flood Warning
Risk of dangerous and rapidly developing flood conditions
Heat Advisory
Dangerous heat
Wind Advisory
Strong or damaging winds
Coastal Flood Warning
Risk of flooding in coastal or low-lying areas
Fire Danger Warning
Elevated wildfire conditions
Dense Fog Advisory
Reduced visibility
Weather Alert Response Includes
- Alert ID
- Event type
- Severity
- Urgency
- Certainty
- Effective time
- Expiration time
- Issuing authority
- Geographic polygon
- Description
- Recommended actions
Comprehensive detection and alerting across all high-impact weather phenomena
— from tropical cyclones to winter storms.
Government-Issued Alerts (US and Canada)
Severe Weather Alerts (United States)
● Real-time severe weather alerts for the entire US
● Alerts are provided as soon as they are issued by the National Weather Service
● No other weather provider offers real-time access to this information in so many unique technical formats.
Environment Canada Severe Weather Alerts (Canada)
● Real-time severe weather alerts for the entire US
● Alerts are provided as soon as they are issued by the National Weather Service
● No other weather provider offers real-time access to this information in so many unique technical formats.
Custom Alerts and Advisories (available worldwide)
Custom Alert Email
- Custom alerts can be generated for any specific weather criteria
- Alert criteria can be in the past based on climate data or in the future based on weather forecasts
- Weather alerts can be generated that incorporate both past and future weather data
- Custom alerts can be sent out via email to specific user groups, via FTP, or via SMS using carrier email-to-SMS transmission
Current Condition Observation Alerts
- Alert notifications of severe weather events based on thousands of global, real-time current condition reports.
- Alerts are issued against standard criteria or customized for client requirements.
Forecasted Significant Weather
- Forecasted Significant Weather highlights areas with the most significant weather as compared to climatology.
- Created to be used in conjunction with Severe Weather Advisories.
- Forecasted Significant Weather uses a ranking of 0-100 to indicate the significance of weather in a particular location with a focus on precipitation, winds, and temperature.
Severe Weather Advisories
Global Severe Weather Advisory System
First and only worldwide severe weather advisory system.
● Our advisories inform people around the globe of potentially dangerous or severe weather conditions in their local area BEFORE they happen.
● Advisories are updated four times daily and are available for 85,000+ worldwide locations.
● Advisories cover the next 24 hours.
● Options for upcoming 6 hours, 48 hours, and upcoming 5 days are also available.
Examples include:
- Precipitation
- Lightning Strider Alerts (US only)
- High Winds
- Freeze Alerts
- Ice Accretion
- Extreme Heat Alerts
- Hail Potential
- Tornado Potential
- Surf Alerts
- Tropical Storm Updates
Hail
Real Time Hail Tracking (USA)
● Track the size and movement of storm cells containing hail based on Doppler Radar signatur
● Provides the probability of hail associated with a storm cell
● Indicates the maximum hail diameter reported
● Available through our API in XML format
● Data also available in a map tile interface with scroll-overs for additional detail
Hail Forecast (Global)
Sample Hail Forecast
Hail forecast is available as a Cloud Weather Service (CWS) plug-in.
- Forecast for a probability of significant hail is available out to 7 days.
- The criteria for significant hail has been defined by the Storm Prediction Center
Flood
Globally available flood risk is based on past, current, and future precipitation compared to typical during a given period.
Flood Risk
● Precipitation observations and forecasts are dynamically integrated over time to capture flood potential as it relates to given conditions across the landscape.
● Flood forecasts are available day-by-day at 10km with regional scales to 1km.
● Flood risk is broken into 5 categories – Low, Moderate, High, Very High, and Severe.
● Data can be delivered as kmz/kml, map tile, geojson, or geotiff/shapefile/geopackage
Icing Index
Icing index for any global location is available via CustomWeather’s Cloud Weather Service.
Icing Forecasts
● Surface forecasts for categorical freezing rain
● Categorical ice pellets
● Percentage frozen precipitation
● Frozen rain
● freezing rain
● highest tropospheric freezing level geopotential height
● 0°C isotherm geopotential height
Lightning (North America)
Accuracy within 150 meters | Near 100% efficiency rating | Timing to the microsecond | Reporting within 12 seconds.
Flexible Data Access
All lightning datasets are available through our APIs for seamless integration into your systems:
Weather Essentials API
Cloud Weather Services API
Formats: JSON, XML
Formats: netCDF (gridded datasets)
Real-time lightning densityLightning probability forecasts
Ideal for modeling, GIS, and advanced analytics workflows
Lightning Alerts via Email
● Real-time lightning alerts via email can be delivered for specific locations across North America
● Alerts are sent according to user-defined distance thresholds (typically 5 or 10 miles)
Example alert via email:
Notification Rule:Lightning - 10 mi
Lightning alert within 10mi 30min
Lightning Distance: 7.31 miles
Stroke Location: Lat: 29.6919 Lon: -95.1554
Type: IC
Peak Current: +11.658 kA
Activated Time: 08/18/2021 02:41:41 PM CDT
Real Time Lightning Intelligence at 1 km Resolution
● CustomWeather delivers high-resolution lightning intelligence across the Continental United States, combining real-time observations with short-term predictive insight. Built for precision and speed, this dataset helps organizations detect, monitor, and respond to lightning risk as it evolves.
Lightning Probability Forecasts (0–60 Minutes)
● In addition to real-time observations, CustomWeather now provides short-term lightning probability forecasts across the Continental U.S.
Forecast horizon
● Next 30 minutes
● Next 60 minutes
Key benefits:
● Anticipate lightning risk before it occurs
● Improve decision-making lead time
● Reduce exposure for personnel, assets, and operations
● Continuously updated for evolving storm conditions
Lightning Density Data (Real-Time)
Our lightning density dataset provides cloud-to-ground lightning activity at 1 km spatial resolution, measured as:
Flashes per square kilometer per minute
Available time aggregations:
● 1-minute (near real-time precision)
● 5-minute
● 15-minute
● 30-minute
This data enables you to
● Trigger instant lightning alerts
● Monitor strike intensity trends
● Identify rapidly developing storm hazards
● Enhance safety protocols for outdoor operations
Built for High-Stakes Applications
- Aviation & Airports
- Energy & Utilities
- Outdoor Events & Recreation
- Construction & Infrastructure
- Insurance & Risk Management
- Government & Emergency Services
Why CustomWeather?
- High-resolution (1 km) nationwide coverage
- Minute-level updates for real-time awareness
- Integrated observations + forecasts
- Developer-friendly APIs
- Proven reliability for mission-critical operations