Spline chart

Here we have use foolwing features:

• Axis
• Negative values

We have here 4 temperature channels. They have all the same unit °C, so it is fine to put them all at same axis.

By default, it would look like this:

Let's pimp it a bit:

• Show us the min. and max. values, for inside temperature also the last one (if you take a look a look at "today", it will be the "actual" value)
• Show us inside temperatures below 24°C in an other color

The inside temperature is more or less in an other value range like the others, so let's put it on its own (right) axis: