Radio waves in the 400- to 900-MHz range may pass through some obstructions, depending on their composition, but will be absorbed or reflected otherwise. This means that the signal can potentially reach as far as the horizon, as long as there are no physical barriers to block it. Elevating LoRa devices—placing them on rooftops or mountaintops, for example—will maximize their range. Other factors, such as antenna gain, will also have a large impact on range.
Range depends on numerous factors—indoor/outdoor gateways, payload of the message, antenna used, etc. On average, in an urban environment with an outdoor gateway, you can expect up to 2- to 3-km-wide coverage, while in the rural areas it can reach beyond 5 to 7 km.