Compared to the other cities in California and cities in all other U.S. states, how safe is Monrovia, CA? From the gauges displayed above, you will notice that Monrovia, CA has been ranked safer than 69% of other cities in the state of California. In addition, Monrovia, CA is safer than 52% of cities in the entire United States. To achieve these results, all California and United States cities were analyzed to determine how many locations had a lower crime rate than Monrovia, CA. By studying this data, it was possible to determine that Monrovia, CA is above average in safety when compared with other United States cities.