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Wind Speed Datasets

The Calcs.com GIS API provides access to authoritative wind speed maps for structural engineering design, covering both US and European standards.

US Wind Data

We support both ASCE 7-22 (current) and ASCE 7-16 (legacy) wind speed maps.

ASCE 7-22 Wind Datasets (Recommended)

ASCE 7-22 defines four risk categories based on building occupancy and consequences of failure:

Dataset	Risk Category	Description	Typical Buildings
us_wind_asce7_22_rc1	I	Low hazard	Agricultural, minor storage
us_wind_asce7_22_rc2	II	Standard occupancy	Most buildings, residences
us_wind_asce7_22_rc3	III	Substantial hazard	Schools, jails, power plants
us_wind_asce7_22_rc4	IV	Essential facilities	Hospitals, fire stations, emergency shelters

ASCE 7-16 Wind Datasets (Legacy)

Dataset	Risk Category	Description
us_wind_asce7_16_rc1	I	Low hazard
us_wind_asce7_16_rc2	II	Standard occupancy
us_wind_asce7_16_rc3	III	Substantial hazard
us_wind_asce7_16_rc4	IV	Essential facilities

Data Specifications

• Standards: ASCE 7-22 Chapter 26 (default), ASCE 7-16 Chapter 26
• Return Period: Varies by Risk Category (300-1700 years)
• Units: mph
• Resolution: Contour-based with interpolation

US Tornado Data (ASCE 7-22)

ASCE 7-22 introduced tornado wind speed maps for Risk Categories III and IV only:

Dataset	Risk Category	Description
us_tornado_asce7_22_rc3	III	Tornado speeds for substantial hazard buildings
us_tornado_asce7_22_rc4	IV	Tornado speeds for essential facilities

Note: Tornado data is only available for Risk Categories III and IV per ASCE 7-22. Risk Categories I and II do not require tornado design.

European Wind Data

Available Datasets

Dataset	Country	Standard	Description
spain_wind	Spain	CTE DB SE-AE	Basic wind velocity map
dk_base_wind_speed	Denmark	DS/EN 1991-1-4 DK NA	Fundamental basic wind velocity
gb_base_wind_speed	United Kingdom	BS EN 1991-1-4 UK NA	Basic wind velocity
ke_base_wind_speed	Kenya	KS EN 1991-1-4	Fundamental wind velocity
no_base_wind_speed	Norway	NS-EN 1991-1-4 NA	Basic wind speed
se_base_wind_speed	Sweden	SS-EN 1991-1-4	Basic wind velocity

Note: For Nordic countries (Sweden, Norway), wind speeds are defined by geographic zones rather than contour maps. The /gis/wind endpoint handles this automatically - no special configuration needed.

Data Specifications

• Standard: EN 1991-1-4 with National Annexes
• Return Period: 50 years (typical)
• Units: m/s
• Terrain: Open country terrain category II
• Height: 10m above ground level

API Endpoints

Endpoint	Use Case	API Reference
/gis/wind	Recommended - Get all wind speeds for a location (all risk categories)	Wind API
/gis/tornado	Get tornado speeds for a location (US only, RC III & IV)	Tornado API
/gis/environmental_loads	Get all environmental data (wind, tornado, snow, seismic) in one call	Environmental Loads API

Tip: Use /gis/wind for wind data and /gis/tornado for tornado data. These endpoints automatically select the correct datasets and return all risk categories. Use /gis/environmental_loads if you need wind, snow, and seismic data together.

Quick Example

Get wind speeds for New York City (defaults to ASCE 7-22):

Code
 
curl "https://api.calcs.com/gis/wind?latitude=40.7128&longitude=-74.0060" \
  -H "Authorization: Bearer YOUR_API_KEY"

Response:

Code
 
{
  "location": {
    "latitude": 40.7128,
    "longitude": -74.006,
    "country": "United States",
    "countryCode": "US",
    "standard": "ASCE 7-22"
  },
  "values": [
    { "riskCategory": "I", "value": 107.7, "unit": "mph" },
    { "riskCategory": "II", "value": 115.6, "unit": "mph" },
    { "riskCategory": "III", "value": 125.2, "unit": "mph" },
    { "riskCategory": "IV", "value": 129.7, "unit": "mph" }
  ],
  "_metadata": {
    "datasetsUsed": ["us_wind_asce7_22_rc1", "us_wind_asce7_22_rc2", "us_wind_asce7_22_rc3", "us_wind_asce7_22_rc4"]
  }
}

Using ASCE 7-16 (Legacy)

To get ASCE 7-16 wind speeds, add the standard parameter:

Code
 
curl "https://api.calcs.com/gis/wind?latitude=40.7128&longitude=-74.0060&standard=ASCE%207-16" \
  -H "Authorization: Bearer YOUR_API_KEY"

Response:

Code
 
{
  "location": {
    "latitude": 40.7128,
    "longitude": -74.006,
    "country": "United States",
    "countryCode": "US",
    "standard": "ASCE 7-16"
  },
  "values": [
    { "riskCategory": "I", "value": 107.4, "unit": "mph" },
    { "riskCategory": "II", "value": 115.2, "unit": "mph" },
    { "riskCategory": "III", "value": 126.7, "unit": "mph" },
    { "riskCategory": "IV", "value": 129.5, "unit": "mph" }
  ],
  "_metadata": {
    "datasetsUsed": ["us_wind_asce7_16_rc1", "us_wind_asce7_16_rc2", "us_wind_asce7_16_rc3", "us_wind_asce7_16_rc4"]
  }
}

Note: Many US jurisdictions still use ASCE 7-16. Check your local building code requirements to determine which standard applies.

European Locations

For European locations (e.g., Stockholm, Sweden):

Code
 
curl "https://api.calcs.com/gis/wind?latitude=59.3293&longitude=18.0686" \
  -H "Authorization: Bearer YOUR_API_KEY"

Response:

Code
 
{
  "location": {
    "latitude": 59.3293,
    "longitude": 18.0686,
    "country": "Sweden",
    "countryCode": "SE",
    "standard": "EN 1991-1-4"
  },
  "values": [
    { "riskCategory": null, "value": 24, "unit": "m/s" }
  ],
  "_metadata": {
    "datasetsUsed": ["se_base_wind_speed"]
  }
}

Note: Nordic countries return a single value (no risk categories) because EN 1991-1-4 uses a single design wind speed.

Understanding the Data

Interpolation Method

For contour-based datasets, the API uses linear interpolation:

1. Finds the two nearest contour lines
2. Calculates distance-weighted average
3. Returns interpolated value

For locations in flat regions (single contour), that contour value is returned.

Design Considerations

ASCE 7-16

• Basic wind speeds are 3-second gust
• Apply exposure, topographic, and directionality factors
• Consider wind-borne debris regions (hurricane zones)

Eurocode EN 1991-1-4

• Basic velocities are 10-minute mean values
• Apply terrain, orography, and structural factors
• Check National Annex for local modifications

Data Sources

• ASCE 7-22: Based on ASCE 7-22 wind and tornado speed maps (current)
• ASCE 7-16: Based on ASCE 7-16 wind speed maps (legacy)
• Eurocode: National meteorological services and standards bodies
• Updates: Datasets updated when new code editions are published

Related Documentation

• Wind API - Recommended for wind data
• Tornado API - Tornado wind speeds (US only)
• Environmental Loads API - All environmental data in one call
• Snow Data - Ground snow load datasets
• Seismic Data - Seismic design parameters