One of the reasons to people take action to help to protect the environment is the easy access to information and cheap materials which facilitate to come up with a homemade solution.
When individual actions are carried out by numerous inhabitants, for instance, to plant a tree in the neighborhood, it is verified that the air quality turns out better than it was before, and the temperature goes down and changes to a pleasant one.
These actions are noticed by other inhabitants and they may raise awareness of environmental issues. So these inhabitants can feel motivated to contribute and collaborate with them.
On the other hand, individual actions may insinuate that the government does not take their projects to preserve the environment seriously, and which is worse, it can lead to a political apathy – i.e. to spend less money in environment protection policies - it doesn’t put in the necessary effort to tackle the issue and also doesn’t take actions to develop serious and effective projects to fight against environmental destruction.
However, the work of these selfless people who are always producing homemade solutions may result in destructive actions instead of helping the environment. For example, the citizens decide to plant trees along the sidewalks but by lacking of orientation and supervision, the selected tree specimen has shallow roots and in a few years, the street and sidewalks are damaged by it.
Also individual actions have minimal effect without a long-term incentive from the government, social entity or private companies. It is just an isolated contribution which at the end of the day, nobody knows what was done.
Campaigns and social programs are capable of assembling numerous participants to support the cause; it can successfully achieve a great mass of people when properly advertised.
To conclude, in my opinion individual actions can help the weather (or environment – I don’t know what you wanted to say) if the people who are involved in them, work together with the government or entities that can organize a campaign to save (or protect) the environment and advertise it to reach as many people as possible.