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Snow Load Datasets

The Calcs.com GIS API provides access to ground snow load maps for structural engineering design, covering US and Nordic standards.

US Snow Data

We support both ASCE 7-22 (current) and ASCE 7-16 (legacy) ground snow load maps.

ASCE 7-22 Datasets (Default)

ASCE 7-22 provides ground snow load maps for all four risk categories:

Dataset	Risk Category	Description	Typical Buildings
us_snow_asce7_22_rc1	I	Low hazard	Agricultural, minor storage
us_snow_asce7_22_rc2	II	Standard occupancy	Most buildings, residences
us_snow_asce7_22_rc3	III	Substantial hazard	Schools, jails, power plants
us_snow_asce7_22_rc4	IV	Essential facilities	Hospitals, fire stations, emergency shelters

ASCE 7-16 Dataset (Legacy)

Dataset	Description
us_snow_asce7_16	Single ground snow load value (no risk categories)

Important: ASCE 7-16 provides a single ground snow load (pg) value that applies to all risk categories. Risk category adjustments are handled through importance factors in the roof snow load calculation, not through separate ground snow load maps.

Data Specifications

• Standard: ASCE 7-22 Chapter 7 (default), ASCE 7-16 Chapter 7
• Units: psf (pounds per square foot)
• Resolution: Contour-based with interpolation

Note: Some regions may return "Case Study Required" for areas where ground snow loads must be determined through site-specific analysis.

Nordic Snow Data (Eurocode)

Available Datasets

Dataset	Country	Standard	Units
se_snow	Sweden	SS-EN 1991-1-3	kN/m2

Data Specifications

• Standard: EN 1991-1-3 with National Annexes
• Return Period: 50 years (characteristic value)
• Units: kN/m2 (kilonewtons per square meter)
• Method: Region-based lookup (geographic zones)

API Endpoints

Endpoint	Use Case	API Reference
/gis/snow	Recommended - Get ground snow loads for a location (all risk categories)	Snow API
/gis/environmental_loads	Get all environmental data (wind, tornado, snow, seismic) in one call	Environmental Loads API

Tip: Use /gis/snow for snow data. This endpoint automatically selects the correct datasets based on location and returns all risk categories for US locations.

Quick Example

Get ground snow loads for Denver, Colorado (defaults to ASCE 7-22):

Code
 
curl "https://api.calcs.com/gis/snow?latitude=39.7392&longitude=-104.9903" \
  -H "Authorization: Bearer YOUR_API_KEY"

Response:

Code
 
{
  "location": {
    "latitude": 39.7392,
    "longitude": -104.9903,
    "country": "United States",
    "countryCode": "US",
    "standard": "ASCE 7-22"
  },
  "values": [
    { "riskCategory": "I", "value": 38, "unit": "psf" },
    { "riskCategory": "II", "value": 55.4, "unit": "psf" },
    { "riskCategory": "III", "value": 69.7, "unit": "psf" },
    { "riskCategory": "IV", "value": 86, "unit": "psf" }
  ],
  "_metadata": {
    "datasetsUsed": ["us_snow_asce7_22_rc1", "us_snow_asce7_22_rc2", "us_snow_asce7_22_rc3", "us_snow_asce7_22_rc4"]
  }
}

Using ASCE 7-16 (Legacy)

To get ASCE 7-16 ground snow loads, add the standard parameter:

Code
 
curl "https://api.calcs.com/gis/snow?latitude=39.7392&longitude=-104.9903&standard=ASCE%207-16" \
  -H "Authorization: Bearer YOUR_API_KEY"

Response:

Code
 
{
  "location": {
    "latitude": 39.7392,
    "longitude": -104.9903,
    "country": "United States",
    "countryCode": "US",
    "standard": "ASCE 7-16"
  },
  "values": [
    { "riskCategory": null, "value": 10, "unit": "psf" }
  ],
  "_metadata": {
    "datasetsUsed": ["us_snow_asce7_16"]
  }
}

Note: ASCE 7-16 returns a single ground snow load value without risk category breakdown. Many US jurisdictions still use ASCE 7-16—check your local building code requirements.

Nordic Locations

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

Code
 
curl "https://api.calcs.com/gis/snow?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 1991-1-3"
  },
  "values": [
    { "riskCategory": null, "value": 2, "unit": "kN/m2" }
  ],
  "_metadata": {
    "datasetsUsed": ["se_snow"]
  }
}

Note: Nordic countries return a single characteristic snow load value (no risk categories) based on the geographic zone.

Understanding the Data

Ground Snow Load (pg)

The API returns the ground snow load (pg), which is the weight of snow on the ground per unit area. This is the starting point for calculating roof snow loads.

To determine roof snow loads, you must apply:

• Exposure factor (Ce)
• Thermal factor (Ct)
• Importance factor (Is)
• Roof slope factor (Cs)

Country Coverage

Country	Snow Data Available	Standard
US	Yes	ASCE 7-22 (default), ASCE 7-16
Sweden	Yes	EN 1991-1-3
Norway	No	-
Denmark	No	-
UK	No	-
Spain	No	-
Kenya	No	-

Related Documentation

• Snow API - Recommended for snow data
• Environmental Loads API - All environmental data in one call
• Wind Data - Wind speed datasets
• Seismic Data - Seismic design parameters