Abstract: Trends and variability in tropospheric hydroxyl (OH) radicals influence budgets of many greenhouse gases, air pollutant species and ozone depleting substances. Estimations of tropospheric OH trends and variability based on budget analysis of methyl chloroform (CH₃CCl₃), and process‐based chemistry transport models often produce conflicting results. Here we use a previously tested transport model to simulate atmospheric CH₃CCl₃ for the period 1985‐2018. Based on mismatches between model output and observations, we derive consistent anomalies in the inverse lifetime of CH₃CCl₃ (K_G) using measurements from two independent observational networks (NOAA and AGAGE). Our method allows a separation between “physical” (transport, temperature) and “chemical” (i.e., abundance) influences on OH+CH₃CCl₃ reaction rate in the atmosphere. Small increases in K_G due to “physical” influences are mostly driven by increases in the temperature‐dependent reaction between OH and CH₃CCl₃ and resulted in a smoothly varying increase of 0.80 % decade^‐1 . Chemical effects on K_G, linked to global changes in OH sources and sinks, show larger year‐to‐year variations (∼2‐3%), and have a negative correlation with the El Niño Southern Oscillation. A significant positive trend in K_G can be derived after 2001, but it persists only through 2015 and only if we assume that CH₃CCl₃ emissions decayed more slowly over time than our best estimate suggests. If global CH₃CCl₃ emissions dropped below 3 Gg yr^‐1 after 2015, recent CH₃CCl₃ measurements indicate that the 2015‐2018 loss rate of CH₃CCl₃ due to reaction with OH is comparable to its value two decades ago.