The first monarch generation of 2026 began as eggs in the southern US, the offspring of monarchs that had overwintered in Mexico. These first-generation monarchs continued the journey northward, arriving in Wisconsin in late April and May, laying eggs as they moved north. By now, the first 2026 generation has mostly died off and we’re beginning to see adults from the second 2026 generation (the first northern generation) emerging.

The emergence of this new generation is usually indicated by two things – upticks in observations of adult monarchs in good condition and in the density of eggs on milkweed plants as reported by Monarch Larva Monitoring Project volunteers. 2026 started out with low numbers in Wisconsin and throughout monarchs’ northern breeding range, but we’re beginning to see the expected uptick in eggs laid by the second 2026 generation (see graph to the left; the eggs and larvae laid over the past two weeks will become the third 2026 generation!).

While we can’t predict exactly what will play out over the next two months in Wisconsin, the graphs document the possibility of good numbers after a relatively low spring (2025; see graph below left). But they also show that a summer increase isn’t a sure thing (2024; see graph below right). For data going back multiple decades, see more graphs for Wisconsin here.