How to change unit type (metric vs imperial) for Yahoo Weather API with YQL

This is a short example on how to change unit type for Yahoo Weather YQL query. This may be an overlooked bit of information but is covered quite well in the Yahoo! Weather Documentation. Mind you this is the RSS feed documentation but since YQL uses this feed as a backend service, you can pass the same parameters into it as you would if you were using the RSS feed directly. This is done using a feature called remote filters.

Here's what the documentation states:

The optional u (units) parameter indicates the degree units for the weather forecast. By default, Yahoo! Weather returns temperature information in degrees Fahrenheit. Use the u parameter to explicitly specify the degree units in Fahrenheit (f) or Celsius (c). The units parameter is case sensitive. For example, to get the weather forecast in Sunnyvale, CA in Celsius:

Note that choosing Celsius degree units changes all the weather units to metric, for example, wind speed will be reported as kilometers per hour and barometric pressure as millibars.

That's great! So lets see how it behaves. I used the following query to test this (here's a YQL Console link to it):

YQL

select units from weather.forecast

where u='c'

and woeid in (select woeid from geo.places where text="Brisbane, Australia")

Note that the units information is returned in Metric units.

When I change the 'u' parameter to 'f', units are returned in Imperial...

So there you go! Quite easy to do. Here's exactly what you get when you change the unit type:

Set to 'c':

Distance - kilometres
Speed - kilometres per hour
Pressure - millibars
Temperature - degrees Celsius

Set to 'f':

Distance - miles
Speed - miles per hour
Pressure - pounds per square inch
Temperature - degrees Fahrenheit

-i