Grafana is a dashboard frontend for the postgres database. Queries can be entered in the graphical interface and plotted. The raspberry pi hosts the grafana server.
Find the raspberry pi's local ip address. You could check your router's list of connect devices. The raspberry pi should show up as aqpi. Alternatively, plug the raspberry pi into a monitor and using a keyboard open the terminal application and run ip addr show. If connected over wifi, use the ip address listed under wlan0. If over ethernet, use eth0. Enter the IP address into your browser while connected to the same network the raspberry pi is on.
I have added four plots and three statistics to the grafana dashboard. The plots of temperature, humidity, and AQI use the timescaledb function time_bucket to plot averages over a window dependent interval. The width of the interval is determined by the PPI (points per interval) variable accessed by clicking the gear icon in top right corner of the dashboard. The default is to plot 50 points. Some amount of averaging is required to smooth the sensor data. The fourth plot, "Sensor Readings per Hour", should reliably read 60. This indicates the raspberry pi is reading the sensors once per minute without errors. This frequency is defined in read_sensors.py.