There is interest in the comparison of accelerated corrosion tests to corrosion performance in natural atmospheric environments. Currently, there are some concerns that accelerated corrosion testing may not accurately predict performance in natural atmospheric environments. This provided motivation to compare the corrosion behavior of aluminum, copper, magnesium, steel and zinc alloys exposed in a variety of natural atmospheric environments such as rainforest, marine, arid, volcanic and light industrial to a modified GM 9540P cyclic-corrosion test. The modified GM 9540P cyclic-corrosion test was run for 6, 12, 24, 36, and 48 cycles. Results indicated a lack of agreement in the ordering of alloy performance between the accelerated tests and performance in the natural atmospheric environments. Hence, the use of accelerated corrosion testing may not always result in the optimal selection of materials for field use. The data generated also provide the equivalent days of outdoor exposure per cycle of the modified GM 9540P test for all of the alloys.