It's hard to quantify, but it does seem like regional predictions are less accurate than continental, and predictions about rainfall are less accurate than temperature. However, predictions of rising temperature are essentially guaranteed.

> There is considerable confidence that climate models provide credible quantitative estimates of future climate change, particularly at continental scales and above ...

> Confidence in model estimates is higher for some climate variables (e.g., temperature) than for others (e.g., precipitation).

> Over several decades of development, models have consistently provided a robust and unambiguous picture of significant climate warming

Sources:

[1] https://oceanservice.noaa.gov/education/pd/climate/factsheet... [2] https://archive.ipcc.ch/publications_and_data/ar4/wg1/en/faq...

https://en.wikipedia.org/wiki/History_of_climate_change_scie...

>Also in 1969, Mikhail Budyko published a theory on the ice–albedo feedback, a foundational element of what is today known as Arctic amplification.

This is generally confirmed by observations, as seen in the graph:

https://en.wikipedia.org/wiki/Polar_amplification

I assume four decades should be enough. I don't know about precipitation modeling, that stuff's really hard and the variance is huge.