# Sessions & Weather (event.json) (/docs/assetto-corsa-competizione/sessions-and-weather)



`event.json` defines your race weekend — the track, the sessions, and the weather.

```json
{
    "track": "spa",
    "preRaceWaitingTimeSeconds": 80,
    "sessionOverTimeSeconds": 120,
    "ambientTemp": 22,
    "cloudLevel": 0.2,
    "rain": 0.0,
    "weatherRandomness": 1,
    "configVersion": 1,
    "sessions": [
        { "hourOfDay": 13, "dayOfWeekend": 1, "timeMultiplier": 2, "sessionType": "P", "sessionDurationMinutes": 20 },
        { "hourOfDay": 14, "dayOfWeekend": 2, "timeMultiplier": 2, "sessionType": "Q", "sessionDurationMinutes": 10 },
        { "hourOfDay": 16, "dayOfWeekend": 3, "timeMultiplier": 1, "sessionType": "R", "sessionDurationMinutes": 30 }
    ]
}
```

Sessions [#sessions]

Each entry in `sessions` is one session, run in order. `sessionType` is:

* **`P`** — Practice
* **`Q`** — Qualifying
* **`R`** — Race

| Field                    | Meaning                                    |
| ------------------------ | ------------------------------------------ |
| `sessionDurationMinutes` | Length of the session                      |
| `hourOfDay`              | In-game start hour (0–23)                  |
| `dayOfWeekend`           | `1` = Friday, `2` = Saturday, `3` = Sunday |
| `timeMultiplier`         | How fast in-game time passes               |

Weather [#weather]

| Field               | Meaning                                              |
| ------------------- | ---------------------------------------------------- |
| `ambientTemp`       | Air temperature (°C)                                 |
| `cloudLevel`        | `0.0` clear → `1.0` overcast                         |
| `rain`              | `0.0` dry → `1.0` heavy rain                         |
| `weatherRandomness` | `0` = static, higher = more dynamic/variable weather |

<Callout type="info">
  With `weatherRandomness` above 0, ACC generates realistic changing conditions around your `cloudLevel`/`rain` baseline — so a `0.2` cloud level with randomness `3` gives a mostly-dry weekend with the chance of weather rolling in.
</Callout>

Build sessions and weather visually with the [ACC Config Generator](https://xgamingserver.com/tools/assetto-corsa/acc-config), then drop `event.json` into `cfg/`.