There are thousands of sensors around the city. You can get a sense of shade-vs-sun temperatures by the spread of numbers you see (on cloudy days, the reported temperatures will be much closer together, while on sunny days, sensors in the sun will report elevated temperatures.)
You do need to make sure to disable indoor sensors, and keep in mind that some sensors are faulty. (I've seen some that have been reporting a constant temperature for years.)
I don't understand why it includes indoor sensors at all let alone by default. Why would I want to know the temperature inside some random building?
Add location_type=0 to only get outdoor sensors
Mr. Chilly is one of those niche apps that sparks joy and reminds me of the early app days.
It's an excellent iOS app: https://mr-chilly.com/
My goal was to do something similar as a Claude Code skill
Usually what I want the weather for is to choose what to wear, not to put in a bash script or an LLM or something.
Made it in about 5 minutes with v0.
https://v0-weather-app-one-coral.vercel.app/
Surprisingly, Lands End is the highest temp right now.
Is that the source of the data?
You should use Purple Air if you want to make it more focused https://www2.purpleair.com/