WhenToBird

Stelgidopteryx serripennis · Hirundinidae

When Do Northern Rough-winged Swallows Arrive in Utah?

Adult Northern Rough-winged Swallow
Photo: Peter Chen 2.0, CC BY 4.0 via iNaturalist

Northern Rough-winged Swallows reach Utah in the second week of March, are common by early April, peak in early May (13% of checklists), and most are gone by early September.

When to look

First arrivalsMar 8-14the second week of March
Common byApr 1-7early April
PeakMay 1-7early May
Most gone bySep 1-7early September

Best: early May. First arrivals the second week of March; most are gone by early September. Peak: on about 13% of Utah checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Maruncommon
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Julcommon
  8. Augcommon
  9. Sepcommon
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

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

0%5%10%15%Jan 1-7: 0% of 10857 checklistsJan 8-14: 0% of 8333 checklistsJan 15-21: 0% of 8360 checklistsJan 22-31: 0% of 10516 checklistsFeb 1-7: 0% of 7416 checklistsFeb 8-14: 0.1% of 8082 checklistsFeb 15-21: 0.1% of 9643 checklistsFeb 22-28: 0.4% of 7960 checklistsMar 1-7: 1.0% of 7998 checklistsMar 8-14: 1.0% of 8581 checklistsMar 15-21: 1.9% of 8637 checklistsMar 22-31: 2.4% of 13006 checklistsApr 1-7: 4.5% of 10562 checklistsApr 8-14: 7.6% of 11694 checklistsApr 15-21: 11% of 11382 checklistsApr 22-30: 13% of 16626 checklistsMay 1-7: 14% of 13523 checklistsMay 8-14: 12% of 14714 checklistsMay 15-21: 13% of 13711 checklistsMay 22-31: 10% of 16546 checklistsJun 1-7: 8.7% of 10284 checklistsJun 8-14: 7.9% of 9530 checklistsJun 15-21: 7.9% of 8854 checklistsJun 22-30: 6.7% of 10566 checklistsJul 1-7: 6.3% of 7987 checklistsJul 8-14: 6.8% of 7471 checklistsJul 15-21: 6.7% of 7240 checklistsJul 22-31: 7.4% of 9329 checklistsAug 1-7: 7.3% of 6521 checklistsAug 8-14: 7.2% of 6423 checklistsAug 15-21: 7.2% of 6208 checklistsAug 22-31: 7.0% of 9089 checklistsSep 1-7: 5.6% of 7081 checklistsSep 8-14: 3.5% of 7306 checklistsSep 15-21: 1.8% of 7208 checklistsSep 22-30: 0.8% of 8876 checklistsOct 1-7: 0.3% of 7265 checklistsOct 8-14: 0.2% of 7226 checklistsOct 15-21: 0.1% of 7007 checklistsOct 22-31: 0.1% of 8443 checklistsNov 1-7: 0.1% of 6711 checklistsNov 8-14: 0% of 6290 checklistsNov 15-21: 0% of 6169 checklistsNov 22-30: 0% of 8228 checklistsDec 1-7: 0% of 6011 checklistsDec 8-14: 0% of 6044 checklistsDec 15-21: 0% of 6721 checklistsDec 22-31: 0% of 9982 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 Utah 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 Utah

Best counties

Share of checklists at the peak
  1. Morgan CountyBest late July · 61 checklists that week, 3,178 in all20%
  2. Summit CountyBest the second week of May · 403 checklists that week, 13,829 in all20%
  3. Utah CountyBest mid August · 845 checklists that week, 70,971 in all19%
  4. Duchesne CountyBest the second week of May · 47 checklists that week, 2,692 in all19%
  5. Washington CountyBest late April · 2606 checklists that week, 43,893 in all18%
  6. Wasatch CountyBest the second week of May · 277 checklists that week, 7,780 in all17%

Best spots

Share of checklists at the peak
  1. Mill CreekSalt Lake County, best late April · 31 checklists that week, 999 in all91%
  2. HarrisburgWashington County, best the second week of April · 24 checklists that week, 153 in all72%
  3. State of Utah Department of Natural Resources 3Salt Lake County, best the second week of May · 35 checklists that week, 1,183 in all71%
  4. Santa Clara RiverWashington County, best late March · 25 checklists that week, 379 in all69%
  5. Harrisburg CanyonWashington County, best late March · 20 checklists that week, 676 in all68%

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

Best time of day

In Utah, the Northern Rough-winged Swallow is most often listed on checklists started between 6 and 8 am (8.0% of those checklists).

0%5%10%15%12 am: too few checklists (242) to judge1 am: too few checklists (178) to judge2 am: too few checklists (169) to judge3 am: too few checklists (162) to judge4 am: too few checklists (284) to judge5 am: too few checklists (1984) to judge6 am: 11% of 11714 checklists7 am: 6.9% of 33209 checklists8 am: 5.3% of 46944 checklists9 am: 4.7% of 46290 checklists10 am: 4.1% of 43144 checklists11 am: 4.0% of 36893 checklists12 pm: 4.3% of 32758 checklists1 pm: 3.4% of 30142 checklists2 pm: 3.4% of 29414 checklists3 pm: 3.4% of 29491 checklists4 pm: 3.9% of 29154 checklists5 pm: 5.3% of 22256 checklists6 pm: 6.7% of 17383 checklists7 pm: 6.8% of 13099 checklists8 pm: too few checklists (6647) to judge9 pm: too few checklists (1753) to judge10 pm: too few checklists (599) to judge11 pm: too few checklists (307) 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
January0%0%0%0%
February0%0.1%0.1%0.4%
March1.0%1.0%1.9%2.4%
April4.5%7.6%11%13%
May14%12%13%10%
June8.7%7.9%7.9%6.7%
July6.3%6.8%6.7%7.4%
August7.3%7.2%7.2%7.0%
September5.6%3.5%1.8%0.8%
October0.3%0.2%0.1%0.1%
November0.1%0%0%0%
December0%0%0%0%

Neighboring states

  • Wyoming: arrives mid April, 5 weeks later than Utah
  • Nevada: arrives the second week of March, in the same week than Utah
  • Colorado: arrives the second week of April, 4 weeks later than Utah
  • Idaho: arrives late March, 2 weeks later than Utah

Common questions

When do Northern Rough-winged Swallows arrive in Utah?
Northern Rough-winged Swallows reach Utah in the second week of March, are common by early April, peak in early May (13% of checklists), and most are gone by early September.
When do Northern Rough-winged Swallows leave Utah?
Most Northern Rough-winged Swallows have left Utah by early September, when reports fall below half their usual rate. Stragglers are still reported until mid September.
When is the best time to see a Northern Rough-winged Swallow in Utah?
The Northern Rough-winged Swallow is reported most often in early May, on about 13% of Utah checklists.
Where in Utah are Northern Rough-winged Swallows seen most often?
By county, Morgan County, Summit County, and Utah County have the highest peak reporting rates for the Northern Rough-winged Swallow (counties with at least 200 checklists).