I can confirm the free plan doesn't get multi-day forecast data. I just signed up and asked for forecast from the api. I got current conditions and today's forecast. It still appears that to get more than today's forecast you'd have to take the $80/mo plan. The $4.95/mo (reduced from $20) does not appear to provide multi-day forecast data.
On the plus side, they do provide images for the current condition. So you'd have that provided by the service instead of hoping it stays on Github or having to host your own.
Honestly, $5/mo isn't terrible. I'd do that if I could get a couple days forecast in the deal and be assured it isn't just an "introductory deal" that is going to expire in a few months.
