When does California poppy bloom in Oregon?

Most often in July. Across 464 dated, research-grade observations of Eschscholzia californica in Oregon, the flowering season runs roughly April to October.

Peak July In flower 464 Examined 511 State Oregon

Flowering 464 in flower of 511 examined

20%

90%

98%

94%

100%

96%

94%

89%

70%

33%

Proportion of examined Eschscholzia californica in Oregon in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	1	5	20%	4% to 62%
Feb	0	4	too few examined
Mar	0	7	0%	0% to 35%
Apr	88	98	90%	82% to 94%
May	186	190	98%	95% to 99%
Jun	84	89	94%	88% to 98%
Jul	36	36	100%	90% to 100%
Aug	26	27	96%	82% to 99%
Sep	17	18	94%	74% to 99%
Oct	16	18	89%	67% to 97%
Nov	7	10	70%	40% to 89%
Dec	3	9	33%	12% to 65%

Peak flowering in Jul. Each bar is the share of Eschscholzia californica in Oregon observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 464 of 511 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. One month has fewer than 5 examined observations, so no proportion is drawn for it. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.wt38fd.

What this is, and what it is not

This is a record of when people in Oregon found Eschscholzia californica in flower, not a forecast. It is computed only from observations made in Oregon, so it is not the species’ global average dragged onto a map: the same plant flowers on different dates in different places, and that is the entire point of the page.

It will not tell you what your particular plant will do this year. Bloom time moves with the season, with altitude, and with the weather, and a warm February pulls everything forward. We publish the distribution and the sample size, and we refuse to draw a month that too few people examined.

The plant

Eschscholzia californica

California poppy

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in Oregon. Every record achieved iNaturalist quality grade Research, which is applied upstream at export. 10.15468/dl.wt38fd. Retrieved 2026-07-14.
World Flora Online Plant List. The accepted name. CC0. Retrieved 2026-07-12.