I feel like I have tried pretty hard to find a solution to this challenge, and nothing has come to light except a somewhat unreliable IFTTT action.
I have a HomeKit compatible outdoor switch from iDevices that I want to only switch on when the outside temperature drops below -10C, it powers our block heater for our vehicle here in Canada. I’d like it to shut off when it’s warmer than -10C, but that can wait. I don’t have an outdoor weather sensor that’s HK compatible, so I’m reliable on the iOS Weather app, or similar.
Any pointers or existing solutions are much appreciated!
Without either a sensor reporting temperature values in HomeKit, or something like Homebridge providing a weather service temperature as a value you dont have many options.
Probably the one that would work the best is a Home Automation eg in the morning at 6:30 Add Accessories, Convert to Shortcut you can then go IF weather is less than -10 Then turn on heater.
If you wanted it to check more times of the day you’d have to add additional Automations at different times, or you could just be a bit inventive and eg tie it to a sensor that gets tripped all the time eg Hallway Motion sensor.
I recently built - with a lot of help from members of this forum - a Keyboard Maestro macro that compares the outside temperature with temperature inside my house (from a Hue motion sensor). You could re-use the part that gets the outside temperature from the Dark Sky API. It won’t have the pinpoint accuracy of a sensor right outside your house, but your purposes, the more general weather forecast for your area would probably work. It’s described in my blog post here, but the following image should help you get started. Note that you will need to get a Dark Sky API.
The first AppleScript is the relevant part for you. The blurred section is my API key and the bit after that is my longitude and latitude (it’s cut off in the screen shot.)
I’ve had trouble with the reliability of the IFTTT weather trigger also. I’ve had some luck with making multiple applets/recipes that do basically the same thing but varying the temperature by a degree. The idea is that the engine block heater would have a chance to be turned on if it drops below -8,-9,-10. And if does get triggered 3 times then it doesn’t matter because the heater is already on.
It’s not a great strategy but I have used it for air conditioners and has helped.
