The three surface trends (HadCrut, NOAA and NASA) seem fairly well correlated, although with varying “bumps” toward the end of the year. And RSS is reasonably close the surface trends, albeit with a slightly different annual pattern.
But the UAH monthly trend shows a smooth, broad annual fluctuation through the year. The February trend at 0.18 deg/decade is above all the other trends, while the May trough at only 0.07 deg/decade is only half that month’s trend in the other data sets.
The difference between UAH and RSS global LT average monthly anomalies for two recent periods since the baseline period (which ended in 1998) shows clearly the annual cycle that results in this extreme UAH trend divergence.