No, you do not need to connect your Laser Egg to a Wi-Fi network in order to monitor your air.
However, connecting your Laser Egg to a Wi-Fi network allows you to control it from your phone, change settings remotely, and access certain features. This includes:
- Display readings in different Air Quality indexes (US, China, or India)
- Display temperature in Celsius or Fahrenheit
- Fetch and display local weather forecasts
- Connect to Apple HomeKit
- Connect to IFTTT