Runplanner reminds you before every scheduled run. On Android you also get a weather briefing for your run.
The run reminder
You get a notification like Your 8.0 km run starts soon! with the route, the time and your note. It arrives at the time you chose before the run (30 minutes by default) or at 9:00 that morning, whichever is earlier. For an evening run you're reminded in the morning, so you can plan your day.
Change the timing in Profile → Settings → Scheduling → Run reminder: 15, 30, 45, 60 or 120 minutes before.
The weather briefing (Android)
An hour before your run (or 30 minutes, 2 or 3 hours, set under Weather briefing) Android shows the forecast for your run: temperature, conditions, wind, chance of rain, and a warning when it's muggy.
On iPhone the run reminder works, but the weather briefing doesn't appear yet. Check the Conditions card on the route instead. See Weather and wind.
Allow notifications
Runplanner asks during setup and again when you schedule your first run (Get run reminders?). If you said no, allow notifications for Runplanner in your phone's settings.
Reminders can arrive a few minutes late. Runplanner doesn't ask for permission to set exact alarms, so your phone may bundle the notification with others to save battery.
Tap a reminder to open the route straight away. See Reminders don't arrive if nothing shows up.