15.5.1. Weather Data

Weather data properties held within the weather file of the simulation can be access via the weather item contained within the context object. These values relate to the weather conditions appropriate for the current time step.

The weather item can be accessed from any context item.

Variable	Description	Metric unit	IP unit
context.weather.ws	wind speed	m/s	ft/s
context.weather.wd	wind direction	degrees clockwise from north	degrees clockwise from north
context.weather.to	outside air temperature	°C	°F
context.weather.ta	outside air temperature (as above)	°C	°F
context.weather.twb	outside wet bulb temperature	°C	°F
context.weather.go	outside air moisture	kg/kg	lb/lb
context.weather.rho	outside air relative humidity	%	%
context.weather.igh	global radiation on the horizontal plane	W/m²	Btu/(h·ft²)
context.weather.ifh	diffuse radiation on the horizontal plane	W/m²	Btu/(h·ft²)
context.weather.idn	direct normal radiation	W/m²	Btu/(h·ft²)
context.weather.pat	atmospheric pressure	Pa	psi