Here's a great example Dashboard showing flood monitoring data from the National Weather Service, built on Operations Dashboard for ArcGIS.
You can learn more about Operations Dashboard here,
Another nice Dashboard example, US Army Corp of Engineers Little Rock District created a Story Map with several Dashboards to track rainfall, gauges, and inundation forecasts.
The Stream Guage Dashboard has been very interesting and inspiring. I was wondering if you knew how they changed the background colour of the "Stream Gauge Observations" text box? It's been bugging me for a while now. the rich text widget does not give any native abilities to change this.
> I was wondering if you knew how they changed the background colour of the "Stream Gauge Observations" text box?
The option to change the background color of the Rich Text element is available in the configuration panel of the element:
The screenshot above was taken from Operations Dashboard embedded in ArcGIS Online.
Hope this helps,