Sep 12, 2026
Iowa Hummingbird Season: A Month-by-Month Calendar
Iowa's hummingbird story runs backwards from what most people expect: fall, not spring, is when the state is busiest. Ten years of eBird checklists (2016–2025) put the high point in early September, when nearly one in three checklists statewide includes a hummingbird — well above anything spring produces — as birds that nested farther north funnel through on their way south. One county stands out from the rest all season: Cedar Rapids runs ahead of the statewide average from June through the fall peak, and in early September more than four in ten checklists there include a hummingbird, the highest of any county we track.
The short version: Ruby-throated Hummingbird is Iowa's only breeding species, arriving statewide in late April and building to a real fall peak in early September before a fast exit through October. Rufous Hummingbird is an uncommon fall visitor — the Iowa Ornithologists' Union lists it as Casual, meaning it has been recorded in about half or more of recent years, but not every year. Three further species — Anna's, Mexican Violetear, and Broad-billed Hummingbird — have real accepted Iowa records, though only Anna's has enough documentation to date precisely.
Iowa Hummingbird Season: Quick Reference
| Question | Answer |
|---|---|
| When do they arrive? | Late April statewide — Des Moines about a week ahead of Cedar Rapids and Sioux City |
| When should feeders go up? | By mid-April, statewide |
| When do they nest? | June through July |
| Busiest time? | Early September — nearly one in three checklists statewide, and more than four in ten in Cedar Rapids |
| When do they leave? | Mid-September in Sioux City; early October in Cedar Rapids; mid-October statewide and in Des Moines |
| Anything else to watch for? | Rufous Hummingbird, an uncommon fall visitor in about half or more of recent years — plus rare historic records of Anna's, Mexican Violetear, and Broad-billed Hummingbird |
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The whole year on one page
County-by-county arrival windows, feeder up/down dates, and when to watch for Rufous — sized 8.5" x 11" for easy reference and printing.
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Iowa's Hummingbird Season at a Glance
One chart tells almost the whole Iowa story. Ruby-throated Hummingbird is the state's only species with a real, chartable season — Rufous is genuine but too thin and scattered by year to plot a meaningful curve alongside Ruby-throated's dominant one, so a second normalized chart wouldn't add anything a shared scale doesn't already show clearly here.
The Counties Behind This Page
This calendar draws on ten years of eBird checklist data (2016–2025) from three Iowa counties chosen for genuinely different geography: Woodbury (Sioux City, the Loess Hills and Missouri River), Linn (Cedar Rapids, east-central Iowa), and Polk (Des Moines, central Iowa) — alongside statewide totals.
One thing worth knowing before you read this month by month: Iowa's real show is fall, not spring. Spring numbers only build to about one in five checklists before easing into the June nesting lull. Fall climbs much higher — nearly one in three checklists statewide and more than four in ten in Cedar Rapids — as Ruby-throateds that bred farther north pass through on their way south. If you assume the season peaked back in May, you're missing Iowa's biggest month by a wide margin.
January, February & March: The Quiet Season
No statewide signal. It's too early in the year for arrivals anywhere in Iowa, and feeders can safely stay in storage.
April: The First Scouts
The first Ruby-throated Hummingbirds reach Iowa in the last week of the month — Polk County (Des Moines) about a week ahead of Cedar Rapids and Sioux City, which arrive in the first week of May.
Get your feeder up before the first scout arrives, not after.
Check last year's feeder for cracked seals and worn ports before the season depends on it — a feeder up in mid-April costs nothing, and one still in the garage when the first bird turns up costs you the sighting. AspenPerch® has a built-in ant moat and a Polyperch® comfort perch, so birds rest between sips instead of hovering through the whole meal.
Shop AspenPerch® →May: Arrival Across the State
Sightings climb fast through May in every tracked county, and statewide numbers reach a first high point by the third week before the June lull sets in.
| County | Reliable Arrival |
|---|---|
| Polk (Des Moines) | Late April |
| Linn (Cedar Rapids) | Early May |
| Woodbury (Sioux City) | Early May |
"Reliable arrival" is the first of two weeks in a row when hummingbirds show up steadily on that county's checklists, not the first stray sighting. Des Moines is the one real exception to a single statewide date: it runs about a week ahead of the other two tracked counties.
June: The Nesting Lull
Statewide sightings dip as the spring wave settles into nesting — a real change in behavior, not a sign birds are leaving. Cedar Rapids barely dips at all: it holds steady through the first three weeks of June before easing back in the fourth.
Why nesting season is the demanding one
There's a wrinkle specific to hummingbirds. Most female birds build up a temporary calcium store in their bones, called medullary bone, and draw on it to make eggshell. Hummingbirds have very little of it, so a laying female has less in reserve. Researchers have seen nesting females eating wood ash and other mineral-rich materials, which they think helps replace the calcium that goes into eggs. In one 1994 study, every bird seen eating ash was a female tending a nest.
It's part of why Pop's Nectar includes calcium and electrolytes rather than sugar alone. Nesting females need extra calcium during egg-laying, and plain sugar water has essentially none. Read more on the research behind it.
Shop Nectarlyte® 8 oz →July: Holding, Then Climbing Again
Numbers hold through the back half of nesting before starting to climb again in the last week of July — the first sign of the bigger move still ahead.
Keep pests off without pesticides — hummingbirds rely on small insects for protein, so spraying near a feeder can cost them a food source, not just protect one.
AspenPerch®'s built-in ant moat blocks ants with a water barrier, and HummGuard® Nectar Tips keep bees and wasps out without changing anything for the birds.
Shop HummGuard® →August: The Real Climb
Sightings climb all month. Fewer than one in five checklists statewide include a hummingbird in the first week; by the last week it's close to one in three. Cedar Rapids climbs even faster, to nearly four in ten by month's end.
This is the month to be generous, not economical.
Birds fueling for a long flight south need feeders topped up more often — the large 2lb Nectarlyte® powder or the Nectarade® liquid concentrate keeps you from running out mid-surge.
September: Iowa's Real Peak
The first week of September is Iowa's busiest of the year: nearly one in three checklists statewide includes a hummingbird, well above anything spring produced. Cedar Rapids runs highest of any tracked county that same week, at more than four in ten, before a sharp drop sets in over the rest of the month.
Peak season means real competition at the feeder.
A second feeder and a swing, kept out of sight of each other, give a territorial male his own station instead of a fight over yours.
Shop the Charm Swing →October: The Fast Exit
Most Ruby-throateds are gone by mid-month. Cedar Rapids empties first of the two counties still active in October; Des Moines holds on a little longer, in line with the statewide picture.
This is the planting month.
Nine of the Perfect Little Sanctuary® blend's 12 varieties need or benefit from a cold, moist stretch before they germinate well, and Iowa's winter does that work on its own.
Shop the Perfect Little Sanctuary® blend →November & December: Rufous Watch and Historic Rarities
Ruby-throated Hummingbird is essentially gone from Iowa by November, but late fall is when several of the state's rare visitors have turned up. Rufous Hummingbird is an uncommon Iowa fall visitor — the Iowa Ornithologists' Union lists it as Casual, meaning it has been recorded in about half or more of recent years, but not every year. A scattered bird may still be working a feeder into November.
Iowa also has real accepted records of three further species. Anna's Hummingbird has 2 accepted records, both from Polk County — a bird that stayed nearly a month at a Saylorville feeder in fall 2010, and a second in November 2015. Mexican Violetear and Broad-billed Hummingbird each have 2 accepted Iowa records as well, per the state's official checklist, though specific dates and counties for those aren't as fully documented.
If you see a hummingbird at your feeder in November or December, keep the nectar from freezing, photograph it if you can, and report it.
The Year at a Glance
| Month | What's Happening |
|---|---|
| Jan–Mar | No statewide signal — too early for arrivals |
| April | First scouts, last week of the month; Des Moines about a week ahead |
| May | Fast statewide climb to a first high point by week three |
| June | The nesting lull — Cedar Rapids holds higher than the rest |
| July | Holding, then climbing again by month's end |
| August | The real climb, with Cedar Rapids pulling ahead |
| September | The peak, in week one — highest of all in Cedar Rapids |
| October | Fast exit — Cedar Rapids empties first, Des Moines lingers |
| Nov–Dec | Rufous watch and Iowa's historic rarities |
Frequently Asked Questions
When do hummingbirds arrive in Iowa?
Late April, statewide — Des Moines (Polk County) about a week ahead of Cedar Rapids and Sioux City, which arrive in early May.
When do hummingbirds leave Iowa?
It depends on where you are. Sioux City empties out by mid-September. Cedar Rapids holds on until early October. Des Moines and the state as a whole hold to mid-October.
What's the busiest time for hummingbirds in Iowa?
Early September, not summer. The first week of the month is the busiest of the year statewide, and Cedar Rapids runs higher still that same week.
Do hummingbirds stay in Iowa year-round?
No. Ruby-throated Hummingbird, the state's only breeding species, migrates south every fall. Rufous Hummingbird is an uncommon fall visitor, recorded in about half or more of recent years, but it isn't a resident population.
Is Rufous Hummingbird really in Iowa?
Yes, though it's uncommon. The Iowa Ornithologists' Union lists it as Casual: it has been recorded in Iowa in about half or more of recent years, but not every year, and most sightings come in fall.
Why We Built This Calendar
Pop's Birding has been helping hummingbird lovers for three generations. One of the questions our customers ask most often is "when do hummingbirds arrive and leave my state?" — we built this calendar to give a direct, sourced answer, not a generic one. Iowa is a particularly easy state to get wrong with a single seasonal assumption: most guides talk about "hummingbird season" as if it peaks in summer, but Iowa's own data says the real peak is a fall migration event, not a summer breeding one — and Cedar Rapids, in particular, runs meaningfully hotter than the rest of the state all season, not just at the very end.
How We Built This Calendar
Timing here comes from eBird checklist data (Cornell Lab of Ornithology), 2016–2025, for Iowa statewide and three counties chosen for real geographic spread: Woodbury (Sioux City), Linn (Cedar Rapids) and Polk (Des Moines). Every date was checked against the number of checklists behind it, not just the percentage. Species status comes from the Iowa Records Committee and the Iowa Ornithologists' Union checklist, which is why Rufous appears here as a casual fall visitor rather than a regular one. The county comparison and the spring-versus-fall split are original analysis built for this page, not a repackaging of eBird's own bar charts.
Sources
- eBird bar chart data, Cornell Lab of Ornithology — Iowa statewide and county-level (Woodbury, Linn, Polk), 2016-2025. Source for all month-by-month seasonal figures and the county comparison.
- Iowa Department of Natural Resources. Source for Ruby-throated Hummingbird's status as the state's essentially sole regularly-occurring species.
- Iowa Records Committee Rare Bird Review List and the Iowa Ornithologists' Union Checklist of the Birds of Iowa. Source for official species status, including Rufous Hummingbird's Casual designation and the accepted-record counts for Anna's, Mexican Violetear, and Broad-billed Hummingbird.
- des Lauriers, J. R. (1994). Hummingbirds eating ashes. The Auk, 111(3), 755–756. Documents five nesting female hummingbirds eating wood ash; no males were seen doing so in that study.
- Adam, M. D., & des Lauriers, J. R. (1998). Observations of hummingbirds ingesting mineral-rich compounds. Journal of Field Ornithology, 69, 257–261. Source for hummingbirds' greatly reduced medullary bone and for the mineral-rich materials they eat.
- Werning, S. (2018). Medullary bone is phylogenetically widespread and its skeletal distribution varies by taxon. Journal of Ornithology, 159, 527–543. Source for medullary bone being confirmed in hummingbirds.
Know before they arrive
You don't have to keep this calendar taped to the fridge. Insider Birding Access members get seasonal notes timed to your region — when to have feeders out, what the birds are doing right now, and what's worth doing in your yard this season. We take the guesswork out of the calendar. Joining takes about thirty seconds, and there's 10% off your first order in it.
Join Insider Birding Access →Free to join. 10% off your first order.
Shop Iowa's Hummingbird Favorites
Bethany Sloan has served as General Manager of Pop's Birding since 2010, continuing the legacy of her grandfather, William "Pops" Sloan, inventor of the Original Hummingbird Swing. A lifelong hummingbird enthusiast, educator, and independent researcher, she leads the company's educational content, including its 50-State Hummingbird Guide series, Regional Guide, Species Guide and Hummingbird Learning Center. Bethany combines scientific research, regional migration data, and more than 16 years of hands-on experience to create trusted educational resources for bird enthusiasts across North America.
