MacGillivray's Warblers reach Utah in early May, are common by mid May, peak in early September (7.5% of checklists), and most are gone by mid September.
When to look
First arrivalsMay 1-7early May
Common byMay 15-21mid May
PeakSep 1-7early September
Most gone bySep 15-21mid September
Best: early September. First arrivals early May; most are gone by mid September. Peak: on about 7.5% of Utah checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprrare
Maypeak season
Junpeak season
Julpeak season
Augpeak season
Seppeak season
Octuncommon
Novnot usually seen
Decnot usually seen
Darker months: more checklists report it. Outlined: peak month.
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
0%few checklistsno data
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.
Little Dell ReservoirSalt Lake County, best early July · 21 checklists that week, 1,326 in all49%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Utah, the MacGillivray's Warbler is most often listed on checklists started between 6 and 8 am (5.3% of those checklists).
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
Month
Days 1-7
8-14
15-21
22-end
January
0%
0.1%
0%
0%
February
0%
0%
0%
0%
March
0%
0%
0%
0%
April
0.1%
0%
0.1%
0.2%
May
1.1%
2.9%
4.8%
6.3%
June
7.4%
6.7%
6.9%
7.3%
July
7.5%
7.0%
4.8%
3.4%
August
3.2%
4.8%
5.4%
7.8%
September
8.1%
6.6%
4.9%
2.7%
October
1.1%
0.3%
0.1%
0%
November
0.1%
0.1%
0.1%
0%
December
0%
0.1%
0.1%
0%
Neighboring states
Wyoming: arrives the second week of May, 1 week later than Utah
Nevada: arrives late April, 1 week earlier than Utah
Colorado: arrives early May, in the same week than Utah
Idaho: arrives early May, in the same week than Utah
Common questions
When do MacGillivray's Warblers arrive in Utah?
MacGillivray's Warblers reach Utah in early May, are common by mid May, peak in early September (7.5% of checklists), and most are gone by mid September.
When do MacGillivray's Warblers leave Utah?
Most MacGillivray's Warblers have left Utah by mid September, when reports fall below half their usual rate. Stragglers are still reported until early October.
When is the best time to see a MacGillivray's Warbler in Utah?
The MacGillivray's Warbler is reported most often in early September, on about 7.5% of Utah checklists.
Where in Utah are MacGillivray's Warblers seen most often?
By county, Sanpete County, Morgan County, and Davis County have the highest peak reporting rates for the MacGillivray's Warbler (counties with at least 200 checklists).