Unless there's ways to knowingly change mid-term trends? Weeks, not days or months? With small alterations it would need a huge effort to rapidly change weather or to keep it un-natural for months at a time. Huge!
I think it might be possible to "guide the weather" and influence it slightly over that "medium" time period, but how and why I have no idea. To alter in the short term over a large area would need huge amounts of energy. In the long term the required effort would be gigantic because:

The system self-corrects, it has for millions of years. Unless large events, like super volcanos or comet strikes hit? Things follow a pretty narrow path.

It does, however, change over time. Measured in decades or centuries, millennia even. A "5 year trend" is a blip. That's what AGW is all about: pretending a natural warming trend after the end of the Little Ice Age (1700 - 1850, give or take) is human-made AND natural short warming spells are also 100% human caused.
Notice how cooling spells are utterly ignored by Alarmists, eh? If forced to see them, they too are caused by humans :/