Spotting late Monarchs?

Why are people reporting so many Monarch (and other species) of butterflies later in the year than normally reported? There are several simple reasons.

  1. More people are noticing butterflies, especially Monarch butterflies. The internet has increased the number of people who recognize Monarch butterflies. More people (than in the past) are aware of the dates they should normally be absent in an area. They record and share the dates that they spot Monarch butterflies in their area. In the past, when people would see the exact same species on the exact same place and on the exact same date they didn’t report it. It meant nothing to them.
  2. More people are raising caterpillars indoors. This protects them from nature’s enemies, including cold temperatures. Many of the butterflies spotted were raised indoors. If they had been left outdoors, low temperatures would have killed them. There are more late-season butterflies because people save them from the weather.
  3. Artificial lighting (along with artificially raised temperatures) in communities and around houses often give a false sense of the time of year to caterpillars under the lights. This can prevent some from going into diapause and/or migrating.
Monarchs overwintering at Norma Gibbs Butterfly Park in Huntington, CA
Monarchs overwintering at Norma Gibbs Butterfly Park in Huntington, CA

Late season butterflies aren’t a reason to panic. Nature will take care of them. If they are where it will freeze, they will die unless they are a species that survives freezing temperatures, such as Mourning Cloak butterflies.

Mourning Cloak butterfly

Extra reports of late-season butterflies are a sign of good things: that people are noticing them and reporting them. When more people are aware of butterflies and their natural lives/life-cycles/timing, they are less apt to use insecticides in their gardens. They are more apt to plant butterfly host and nectar plants.

10 thoughts on “Spotting late Monarchs?

  1. Great article… so glad Monarch sightings on the increase. I raise and release monarchs and keep pretty good records… this is latest I’ve ever seen “stragglers” passing through.. love it.. Monarch Waystation #9181.

    Liked by 1 person

  2. December 21st, 2020. Still monarch caterpillars munching the milkweed. Going to bring a chrysalis in that is ready to hatch, because of cooler weather. Wish they would stop laying eggs, until spring!


    1. same here, my girl has been laying since as early as October here in Louisiana. I just brought all I could find in last night, some paralyzed or dying.


  3. A monarch hatched late in my garden on 10/24/21. We had a couple heavy rain storms so I kept it safe in a butterfly net and released it on 10/30/21. I live in NJ and the temps were about 60-65. Will this butterfly have a chance of surviving the migration?


  4. I am in Texas. I found some Monarch caterpillars on my milkweed. We have been having freezing temperatures in the 20’s and 30’s. Will the caterpillars survive? What can I do?


    1. Yes, down to about 45, perhaps a bit cooler. Much cooler and it will die. It can survive cool temperatures only for a limited period of time. They don’t go into diapause like swallowtails. In chrysalis, they continue to develop, but much slower, at cool temperatures. If it stays cool for a month or more, the chrysalis will most likely die.


      1. Hi, I have two monarch chrysalises. One is on a Rosemary I pulled inside a breezeway where the temperatures have not dropped below 50. Another went into Chrysalis a few days later outside, on the side of the garage. I taped a double layer of clear plastic over 3 sides, leaving the bottom edge open. Mid Ohio, our daytime dropped to 45 twice, since then. Our daytime temps have been averaging in the 60 to 70 range, night time temps averaged 45, (I know because I finished a partial paint job on my house on 10/24,sometimes 50, sometimes 37.
        They have been in the Chrysalis stage now since approximately the last week of September. They were huge caterpillars.
        What will happen to them? Do they need nectar before they migrate?
        Thank you,


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