When does western columbine bloom in California?

Most often in January. Across 3,992 dated, research-grade observations of Aquilegia formosa in California, the flowering season runs roughly January to November.

Peak January In flower 3,992 Examined 4,106 State California

Flowering 3,992 in flower of 4,106 examined

100%

87%

93%

95%

98%

99%

98%

88%

96%

80%

56%

Proportion of examined Aquilegia formosa in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	11	11	100%	74% to 100%
Feb	27	31	87%	71% to 95%
Mar	211	227	93%	89% to 96%
Apr	609	643	95%	93% to 96%
May	829	844	98%	97% to 99%
Jun	1058	1071	99%	98% to 99%
Jul	893	904	99%	98% to 99%
Aug	253	259	98%	95% to 99%
Sep	66	75	88%	79% to 94%
Oct	26	27	96%	82% to 99%
Nov	4	5	80%	38% to 96%
Dec	5	9	56%	27% to 81%

Peak flowering in Jan. Each bar is the share of Aquilegia formosa in California 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. 3,992 of 4,106 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 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 California found Aquilegia formosa in flower, not a forecast. It is computed only from observations made in California, 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

Aquilegia formosa

western columbine

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in California. 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.