Does it need to be an iPhone app? Is simply getting an alert via SMS good enough? If so, you could rig something with a raspberry pi.
$0.02
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It is automation of the home, housework or household activity.
Home automation may include centralized control of lighting, HVAC (heating, ventilation and air conditioning), appliances, security locks of gates and doors and other systems, to provide improved convenience, comfort, energy efficiency and security.
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Does it need to be an iPhone app? Is simply getting an alert via SMS good enough? If so, you could rig something with a raspberry pi.
$0.02
Is OP going to carry the Raspberry Pi around with them to City X and City Y?
I’d imagine there are weather apps that can do this.
OP only wants a notification?
Smartthings doess that. Based on weather or temperature or humidity.
Do you just want to know when the official temperature for a given city reaches you set point?
Most people would approach this by having their own local thermometer and triggering off that.
By I have seen an app called Custom Weather Alerts that should do what you are asking.
You could do that in IFTTT. Need to create an account you are allowed three automations for free
kythera-weather-watch
kythera-weather-watch
Yeah, but works only for those in the US, as there is no way to enter international phone numbers
You will need to roll your own with ShortCuts then.