Hemiargus ceraunus
In 3 days ~50% in a week ~80%
Hemiargus ceraunus, the Ceraunus blue, is a species of butterfly in the family Lycaenidae. The species was first described by Johan Christian Fabricius in 1793. It is found in the southwestern United States, southern Texas, Florida and the Florida Keys south through the West Indies, Mexico and Central America to South America. Strays may be found in North Carolina, Missouri, Kansas and Nevada. The habitat consists of open woodland, desert scrub, dunes, pastures, road edges and vacant lots.
The wingspan is 20–30 mm. Adults are on wing year round in Texas and southern Florida and in late summer in other parts of the range. Adults feed on flower nectar. The larvae feed on the flowers and seedpods of various woody legumes, including Chamaecrista fasciculata, Abrus precatorius and Prosopis species. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Padre Island National Seashore | 🇺🇸 United States | |
| 2 | Ría Lagartos Biosphere Reserve | 🇲🇽 Mexico | |
| 3 | Merritt Island National Wildlife Refuge | 🇺🇸 United States | |
| 4 | Bahía de Loreto National Park | 🇲🇽 Mexico | |
| 5 | Everglades National Park | 🇺🇸 United States | |
| 6 | Cabo Pulmo National Park | 🇲🇽 Mexico | |
| 7 | Saguaro National Park | 🇺🇸 United States | |
| 8 | Joshua Tree National Park | 🇺🇸 United States | |
| 9 | Big Cypress National Preserve | 🇺🇸 United States | |
| 10 | Gandoca-Manzanillo Wildlife Refuge | 🇨🇷 Costa Rica | |
| 11 | Cumbres de Monterrey National Park | 🇲🇽 Mexico | |
| 12 | Cañón del Sumidero National Park | 🇲🇽 Mexico |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Santo Domingo | 🇩🇴 Dominican Republic | |
| 2 | San Antonio | 🇺🇸 United States | |
| 3 | San Pedro Sula | 🇭🇳 Honduras | |
| 4 | Torreón | 🇲🇽 México | |
| 5 | Monterrey | 🇲🇽 México | |
| 6 | Austin | 🇺🇸 United States | |
| 7 | Miami | 🇺🇸 United States | |
| 8 | Mesa | 🇺🇸 United States | |
| 9 | Phoenix | 🇺🇸 United States | |
| 10 | Orlando | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Ceraunus Blue sighting in Saguaro National Park on a given day, based on 269 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 8th most-seen of the 354 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
October
In that month about 40% of wildlife watchers report a Ceraunus Blue in Saguaro National Park on a given day, against about 10% in February to May, the lowest months. That is one of Saguaro National Park's driest months, with about 15 mm of rain against 55 mm in July.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Ceraunus Blue sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
7th of 12
Of the 12 parks where we can rate Ceraunus Blue sightings, Saguaro National Park ranks 7th at about 20%. The best odds are in Padre Island National Seashore (United States, about 30%), Ría Lagartos Biosphere Reserve (Mexico, about 30%) and Merritt Island National Wildlife Refuge (United States, about 30%).
Same family: Lycaenidae
The closest relatives of the Ceraunus Blue that you can see in Saguaro National Park (family Lycaenidae, Gossamer-winged Butterflies) are Marine Blue (about 20%), Reakirt's Blue (about 20%) and Gray Hairstreak (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Ceraunus Blue is recorded against all the insects logged in Saguaro National Park (269 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
