WhenToBird

5 swallow species in Montana

When Do Swallows Arrive in Montana?

Adult Tree Swallow
Photo: Carter Dorscht, CC0 1.0 via iNaturalist

Tree Swallows, Barn Swallows, and Cliff Swallows are the swallows you are most likely to see in Montana. Tree Swallows reach Montana in mid March, are common by the second week of April, peak in mid May (39% of checklists), and most are gone by late July.

When to look

First arrivalsMar 15-21mid March
Common byApr 8-14the second week of April
PeakMay 15-21mid May
Most gone byJul 22-31late July

Best: mid May. First arrivals mid March; most are gone by late July. Peak: on about 39% of Montana checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Maruncommon
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Auguncommon
  9. Seprare
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

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

Swallows in Montana, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Tree SwallowMar 15-21Apr 8-14May 15-21Jul 22-3139%
Barn SwallowApr 15-21May 1-7Aug 15-21Sep 8-1416%
Cliff SwallowApr 22-30May 8-14Jul 8-14Aug 8-1413%
Violet-green SwallowMar 22-31Apr 15-21Jul 1-7Aug 1-712%
Bank SwallowMay 1-7May 8-14May 22-31Aug 22-316.6%
0%20%40%60%Tree SwallowBarn SwallowCliff SwallowViolet-green SwallowJanFebMarAprMayJunJulAugSepOctNovDec
  • Tree Swallow
  • Barn Swallow
  • Cliff Swallow
  • Violet-green Swallow
Share of complete checklists reporting each species, by week (4 per month). Gaps: fewer than 10 checklists that week.

Frequency is the share of complete checklists in Montana 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.

Where in Montana

Best counties for Tree Swallow

Share of checklists at the peak
  1. Madison CountyBest late May · 276 checklists that week, 7,008 in all55%
  2. Powell CountyBest mid May · 225 checklists that week, 5,305 in all53%
  3. Deer Lodge CountyBest the second week of May · 306 checklists that week, 8,732 in all52%
  4. Gallatin CountyBest late May · 2837 checklists that week, 66,365 in all51%
  5. Cascade CountyBest late May · 580 checklists that week, 16,190 in all51%
  6. Sanders CountyBest late April · 114 checklists that week, 3,767 in all49%

All swallows in Montana

6 species are reported regularly: 6 are summer visitors.

#SpeciesPatternThrough the yearFirst arrivalsPeakPeak %
1Tree SwallowSummer visitorMar 15-21May 15-2139%
2Barn SwallowSummer visitorApr 15-21Aug 15-2116%
3Cliff SwallowSummer visitorApr 22-30Jul 8-1413%
4Violet-green SwallowSummer visitorMar 22-31Jul 1-712%
5Northern Rough-winged SwallowSummer visitorApr 8-14May 15-2111%
6Bank SwallowSummer visitorMay 1-7May 22-316.6%

Common questions

When do swallows arrive in Montana?
Tree Swallows reach Montana in mid March, are common by the second week of April, peak in mid May (39% of checklists), and most are gone by late July.
When do swallows leave Montana?
Most Tree Swallows have left Montana by late July, when reports fall below half their usual rate. Stragglers are still reported until late August.
When is the best time to see swallows in Montana?
The Tree Swallow is reported most often in mid May, on about 39% of Montana checklists.
Which swallows are in Montana?
Tree Swallow, Barn Swallow, Cliff Swallow, Violet-green Swallow, and Bank Swallow are reported regularly; the Tree Swallow is the most common.