21,017 Quality-Controlled Global Stations Active
Weather Vault™
Instant, certified meteorological datasets formatted for EnergyPlus, PVsyst, Carrier HAP, Trane TRACE, HelioScope, and NREL SAM.
Chicago OHare Intl AP, IL, USA
Mean Annual Temp
10.4 °C
50.7 °F
Max Summer Peak
35.8 °C
96.4 °F
Min Winter Low
-24.5 °C
-12.1 °F
Annual Solar GHI
1,420 kWh/m²
Peak Gust Speed
24.1 m/s
54 mph
Choose Weather Data Format
Select and download your target simulation format below. Hover over any info icon to see supported software and details.
EnergyPlus Weather Format
.epw
FREE
Standard 8-header hourly meteorological dataset (35 variables) for EnergyPlus, OpenStudio, IES-VE.
Primary Software: EnergyPlus, OpenStudio, IES VE, Ladybug Tools, eQUEST.
Content: 35 hourly weather parameters including solar irradiance, dry-bulb, dew-point, humidity, wind, and sky cover.
Content: 35 hourly weather parameters including solar irradiance, dry-bulb, dew-point, humidity, wind, and sky cover.
TMY3 / TMYx Comma-Separated Values
.csv
FREE
NREL standard 68-column dataset with paired data source & uncertainty flags.
Primary Software: PVsyst, HelioScope, NREL SAM, Excel Analysis.
Content: Full 68-field NREL layout with barometric pressure in mbar and paired uncertainty quality flags.
Content: Full 68-field NREL layout with barometric pressure in mbar and paired uncertainty quality flags.
NREL System Advisor Model Solar CSV
.csv
FREE
Streamlined 15-variable format tailored for solar PV, battery, and CSP modeling.
Primary Software: NREL System Advisor Model (SAM), PySAM.
Content: Solar irradiance (GHI, DNI, DHI), ambient temperature, wind, and albedo without building simulation bloat.
Content: Solar irradiance (GHI, DNI, DHI), ambient temperature, wind, and albedo without building simulation bloat.
Peak Heating & Cooling Design Conditions
.ddy
FREE
Statistical 99.6% heating & 0.4% cooling extreme conditions for HVAC equipment sizing.
Primary Software: EnergyPlus, Carrier HAP, Trane TRACE (3D Plus), OpenStudio.
Content: Plaintext EnergyPlus SizingPeriod:DesignDay objects with optical depth clear sky coefficients (taub, taud).
Content: Plaintext EnergyPlus SizingPeriod:DesignDay objects with optical depth clear sky coefficients (taub, taud).
Daysim / Radiance Daylighting Format
.wea
FREE
Mid-hour solar irradiance format for dynamic daylight autonomy (sDA / ASE) modeling.
Primary Software: Daysim, Radiance, DIVA, ClimateStudio, Honeybee.
Content: 6-line header + 8,760 hourly solar beam and diffuse irradiance rows.
Content: 6-line header + 8,760 hourly solar beam and diffuse irradiance rows.
Legacy TMY2 ASCII File
.tm2
FREE
Fixed-width 126-byte ASCII format for legacy DOE-2, eQUEST, and TRNSYS engines.
Primary Software: eQUEST, DOE-2.1E, TRNSYS, Carrier HAP (v5), F-Chart.
Content: Non-delimited, fixed character position ASCII records.
Content: Non-delimited, fixed character position ASCII records.
Custom Hourly Bin Weather Tables
.xlsx / .csv
SUITE APP
Configurable 1°F / 5°F temperature bins with coincident wet-bulb & schedule filtering.
BinMaker Engine Features:
• 1°F, 2°F, 5°F, or 1°C Temperature Bin Steps
• Mean Coincident Wet-Bulb (MCWB) & Enthalpy
• Operating Schedule Filters (24/7, 8-5 M-F, Occupied shifts)
• Direct export to formatted Excel spreadsheets.
• 1°F, 2°F, 5°F, or 1°C Temperature Bin Steps
• Mean Coincident Wet-Bulb (MCWB) & Enthalpy
• Operating Schedule Filters (24/7, 8-5 M-F, Occupied shifts)
• Direct export to formatted Excel spreadsheets.
Certified Meteorological Provenance & Data Quality Assurance
All datasets adhere to World Meteorological Organization (WMO No. 100) standards, NOAA/NCEI Integrated Surface Database ground observations, and ECMWF ERA5 solar irradiance reanalysis. Full scientific specifications, conversion physics, and agency citations are published in our technical reference guide.