I like the idea but this is really hard to read, could use some UI/UX lovin.
I figured a visible graph key to explain the colours could have been useful, although depending on location that could detract from the space available to render the datapoints.
(the default colours and theme also seem relatively sensible, and the mappings are visible under the "Conditions" menu item. I like that daylight hours are subtly hinted using background shading)
1. If one turns on all the sources many of the sources will use same color line.
2. The dark theme doesn’t have enough contrast, the font is gray on a black background.
There are other issues that are hard to put to words, I look at the graph and it’s hard to find a specific date or time.