Proposed solar jar sensor/ cloud sensor
You will need to glue a washer of some sort or cut a circle out of some tin make sure there is a hole cut out in the centre try and keep the glue to a minimum when fixing to the inside glass jar
The idea is you will have your conventional solar jar this may even improve response time to the solar sensor
As soon as night fall comes the solar jar will cooldown due to the Black metal circle losing heat out to space
In whether display there is an option for a solar sensor / cloud sensor
using the air temperature and the differential between the temperature solar jar
The idea behind this you have the normal solar jar for the solar during daytime
and at night time the black metal circle will lose heat out of the jar to space
you may have to alter your solar settings slightly
Solar jar\cloud sensor
Webpage under development