Random Fog Generator

Hey all, About 6 months ago I learned very minimum coding from self teaching… I somehow forgot mostly everything. I had to wipe my computer clean so I lost all scripts… anyways… I have fog in my scene, (2 Particle systems at the moment, maybe more in the future). Im trying to get the effect of the fog randomly appearing at times (maybe one day is foggy and another day is not) and not on at all times.

The script I have now will only enable/disable one particle system at a time, and cannot for the life of me remember what to change it too so both will turn on/off at the same time.

any help is appreciated. thanks

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class FogBehaviour : MonoBehaviour {
   

    void Start () {
        List<GameObject> itemsForRandomEnable=new List<GameObject>();
        foreach (Transform child in transform)
        {
            itemsForRandomEnable.Add(child.gameObject);
        }
        if (itemsForRandomEnable!=null && itemsForRandomEnable.Count>0)
        {
            int itemId=new System.Random().Next(itemsForRandomEnable.Count);
            for (int i=0; i<itemsForRandomEnable.Count;i++)
            {
                if (i==itemId){itemsForRandomEnable[i].gameObject.active=true;}
                else{itemsForRandomEnable[i].gameObject.active=false;}
            }
        }
    }

}

You could have a manager script that references both systems & disables & enables them both whenever you want.