WhenToBird

Calypte costae · Trochilidae

When Do Costa's Hummingbirds Arrive in California?

Adult male Costa's Hummingbird
Photo: David Rankin, CC BY 4.0 via iNaturalist

The Costa's Hummingbird is in California all year. It turns up on about 3.1% of checklists at its peak (late April) and on 1.3% in its quietest week (early October).

When to look

PresentAll year
Peak weekApr 22-30late April
Quietest weekOct 1-7early October

Best: late April. Here all year. Peak: on about 3.1% of California checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Deccommon

Darker months: more checklists report it. Outlined: peak month.

0%1%2%3%4%Jan 1-7: 1.4% of 112336 checklistsJan 8-14: 1.5% of 85518 checklistsJan 15-21: 1.6% of 86488 checklistsJan 22-31: 1.7% of 116174 checklistsFeb 1-7: 1.9% of 75171 checklistsFeb 8-14: 1.9% of 84467 checklistsFeb 15-21: 2.1% of 105683 checklistsFeb 22-28: 2.1% of 83396 checklistsMar 1-7: 2.3% of 77470 checklistsMar 8-14: 2.7% of 75180 checklistsMar 15-21: 2.8% of 80770 checklistsMar 22-31: 2.9% of 114116 checklistsApr 1-7: 2.7% of 84057 checklistsApr 8-14: 2.9% of 83692 checklistsApr 15-21: 3.2% of 89242 checklistsApr 22-30: 3.1% of 114289 checklistsMay 1-7: 3.1% of 85728 checklistsMay 8-14: 2.8% of 91984 checklistsMay 15-21: 3.0% of 75478 checklistsMay 22-31: 3.0% of 106250 checklistsJun 1-7: 2.3% of 70051 checklistsJun 8-14: 2.1% of 67485 checklistsJun 15-21: 1.9% of 66269 checklistsJun 22-30: 1.8% of 79172 checklistsJul 1-7: 1.8% of 62877 checklistsJul 8-14: 1.7% of 60328 checklistsJul 15-21: 1.6% of 59705 checklistsJul 22-31: 1.6% of 83796 checklistsAug 1-7: 1.5% of 60215 checklistsAug 8-14: 1.5% of 60172 checklistsAug 15-21: 1.6% of 59877 checklistsAug 22-31: 1.5% of 89107 checklistsSep 1-7: 1.5% of 72000 checklistsSep 8-14: 1.7% of 71228 checklistsSep 15-21: 1.5% of 76808 checklistsSep 22-30: 1.3% of 100204 checklistsOct 1-7: 1.4% of 76571 checklistsOct 8-14: 1.4% of 80874 checklistsOct 15-21: 1.4% of 74581 checklistsOct 22-31: 1.5% of 97498 checklistsNov 1-7: 1.5% of 70851 checklistsNov 8-14: 1.6% of 72431 checklistsNov 15-21: 1.4% of 66767 checklistsNov 22-30: 1.6% of 94737 checklistsDec 1-7: 1.6% of 65393 checklistsDec 8-14: 1.5% of 67449 checklistsDec 15-21: 1.4% of 83421 checklistsDec 22-31: 1.8% of 124993 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

Frequency is the share of complete checklists in California that listed the bird, 2016–2025. It is not a head count, and it follows where and when people go birding. How to read it.

JanFebMarAprMayJunJulAugSepOctNovDec
today
Second week of November

Each county is shaded by the share of complete checklists there that listed the bird, blended with the weeks either side. Darker is more often. It follows where people watch birds, not how many birds there are. How to read it.

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Where in California

Best counties

Share of checklists at the peak
  1. Riverside CountyBest the second week of March · 2960 checklists that week, 113,541 in all30%
  2. San Bernardino CountyBest late April · 3085 checklists that week, 84,093 in all18%
  3. Kern CountyBest late May · 2005 checklists that week, 47,774 in all16%
  4. Kings CountyBest the second week of July · 42 checklists that week, 3,688 in all12%
  5. Inyo CountyBest the second week of May · 995 checklists that week, 35,713 in all11%
  6. San Diego CountyBest mid March · 9546 checklists that week, 405,465 in all7.5%

Best spots

Share of checklists at the peak
  1. Ohlone ParkAlameda County, best late July · 44 checklists that week, 215 in all100%
  2. Santa Rosa-San Jacinto Mountains National MonumentRiverside County, best mid January · 20 checklists that week, 481 in all96%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In California, the Costa's Hummingbird is most often listed on checklists started between 6 and 8 am (3.9% of those checklists).

0%2%4%6%12 am: too few checklists (1688) to judge1 am: too few checklists (1451) to judge2 am: too few checklists (1402) to judge3 am: too few checklists (1743) to judge4 am: too few checklists (4647) to judge5 am: too few checklists (32158) to judge6 am: 4.9% of 186053 checklists7 am: 3.5% of 444086 checklists8 am: 2.7% of 535846 checklists9 am: 1.7% of 486061 checklists10 am: 1.4% of 411130 checklists11 am: 1.2% of 325798 checklists12 pm: 1.2% of 269132 checklists1 pm: 1.2% of 244762 checklists2 pm: 1.2% of 235420 checklists3 pm: 1.3% of 232365 checklists4 pm: 1.3% of 208688 checklists5 pm: 1.5% of 146104 checklists6 pm: 1.8% of 96867 checklists7 pm: too few checklists (50942) to judge8 pm: too few checklists (14803) to judge9 pm: too few checklists (5561) to judge10 pm: too few checklists (3546) to judge11 pm: too few checklists (2092) to judge12a3a6a9a12p3p6p9p
Share of checklists started in each local hour that reported it. It reflects when people go birding as well as when birds are active. Grey hours have too few checklists (under 2% of the state’s, or under 200) to judge.
Week-by-week table
MonthDays 1-78-1415-2122-end
January1.4%1.5%1.6%1.7%
February1.9%1.9%2.1%2.1%
March2.3%2.7%2.8%2.9%
April2.7%2.9%3.2%3.1%
May3.1%2.8%3.0%3.0%
June2.3%2.1%1.9%1.8%
July1.8%1.7%1.6%1.6%
August1.5%1.5%1.6%1.5%
September1.5%1.7%1.5%1.3%
October1.4%1.4%1.4%1.5%
November1.5%1.6%1.4%1.6%
December1.6%1.5%1.4%1.8%

Neighboring states

  • Nevada: year-round, peaks the second week of March
  • Arizona: year-round, peaks mid March

Common questions

When do Costa's Hummingbirds arrive in California?
The Costa's Hummingbird is in California all year. It turns up on about 3.1% of checklists at its peak (late April) and on 1.3% in its quietest week (early October).
When do Costa's Hummingbirds leave California?
The Costa's Hummingbird does not leave California: it is reported all year, from 1.3% of checklists in early October to 3.1% in late April.
When is the best time to see a Costa's Hummingbird in California?
The Costa's Hummingbird is reported most often in late April, on about 3.1% of California checklists.
Where in California are Costa's Hummingbirds seen most often?
By county, Riverside County, San Bernardino County, and Kern County have the highest peak reporting rates for the Costa's Hummingbird (counties with at least 200 checklists).