If you are wondering how long a Monarch Butterfly lives, the answer is that it depends on how you are asking the question. You see, the Monarch butterfly isn’t born a butterfly. It starts its life as a tiny egg about the size of a pinhead. A caterpillar hatches out of this egg and will spend the next couple of weeks eating milkweed. Once it’s ready, the caterpillar wanders around and tries to find the perfect place to form its chrysalis. It will then spend one to two weeks in the chrysalis before it emerges as a butterfly. Once it reaches the butterfly stage, the Monarch will live between two weeks and 8 months, depending on which generation it is.
So the question of how long a Monarch butterfly lives can be answered in a couple of ways. If you are wondering how long a Monarch butterfly lives as a butterfly, then the answer is two weeks to eight months. But if you are wondering how long a Monarch lives starting as an egg, the answer is 34 days to 9 months.
This is how long a Monarch spends at each stage of its life:
Egg: 3 to 5 days
Caterpillar: 9 to 14 days
Chrysalis: 8 to 15 days
Butterfly: 2 weeks to 8 months*
The length of time spent in the egg, caterpillar, and chrysalis stages does vary depending on temperature. In warmer temperatures, it progresses through each stage faster; in cooler temperatures, it takes a little longer. But from my experience raising Monarchs in our garden, the amount of time spent in each stage almost always falls within the ranges listed above.
*You might have noticed that there is a long span of time when the Monarch reaches the butterfly stage. The Monarch goes through 4 or 5 generations each year between the time it starts its migration north from Mexico in the spring to the time it returns to Mexico for the winter. In most generations, the butterflies live 2 to 6 weeks. The final generation of the year spends the winter in central Mexico. Instead of living the normal 2 to 6 weeks, this final generation can live up to 8 months.
If you are looking for further information on the Monarch’s life cycle and its various stages, please read my “The Monarch Butterfly Life Cycle” article.