When you run the wr_rrd_update.py, it should store the data in sensors.rrd and weather.rrd file in /usr/share/weatherradio. wr_rrd_lastupdate.py creates a JSON document in /usr/share/weatherradio/data The RTsensors_lastupdate should look like that:
{ "BME280_Hum":null, "BME280_Pres":null, "BME280_Temp":null, "DHT_Hum":29.70000076, "DHT_Temp":24.10000038, "MLX90614_Tamb":23.90999794, "MLX90614_Tobj":24.42998695, "TSL2591_Lux":19.059606549999998, "timestamp":1650283441000 }