MacGillivray's Warblers mostly pass through Arizona: the first show up in the second week of August, they are common by mid August, peak in the second week of September (12% of checklists), and most are gone by late September.
When to look
First arrivalsAug 8-14the second week of August
Common byAug 15-21mid August
PeakSep 8-14the second week of September
Most gone bySep 22-30late September
Best: the second week of September. First arrivals the second week of August; most are gone by late September. Peak: on about 12% of Arizona checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Apruncommon
Mayuncommon
Junrare
Julnot usually seen
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 Arizona 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.
Domingo TankCoconino County, best late May · 21 checklists that week, 144 in all65%
Aliso CanyonSanta Cruz County, best the second week of September · 22 checklists that week, 1,888 in all57%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Arizona, the MacGillivray's Warbler is most often listed on checklists started between 5 and 7 am (3.8% 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
0.1%
0.1%
0.1%
0.1%
February
0.1%
0.1%
0%
0.1%
March
0.1%
0.1%
0.1%
0.1%
April
0.4%
1.0%
1.9%
2.4%
May
3.1%
3.1%
2.2%
1.4%
June
0.7%
0.4%
0.3%
0.3%
July
0.3%
0.3%
0.1%
0.1%
August
0.3%
1.2%
5.6%
10%
September
13%
13%
10%
6.7%
October
3.3%
1.4%
0.3%
0.1%
November
0.1%
0%
0%
0.1%
December
0.1%
0.1%
0.1%
0.1%
Neighboring states
New Mexico: arrives late April, 14 weeks earlier than Arizona
Nevada: arrives late April, 14 weeks earlier than Arizona
Utah: arrives early May, 13 weeks earlier than Arizona
California: arrives mid April, 15 weeks earlier than Arizona
Common questions
When do MacGillivray's Warblers arrive in Arizona?
MacGillivray's Warblers mostly pass through Arizona: the first show up in the second week of August, they are common by mid August, peak in the second week of September (12% of checklists), and most are gone by late September.
When do MacGillivray's Warblers leave Arizona?
Most MacGillivray's Warblers have left Arizona by late September, when reports fall below half their usual rate. Stragglers are still reported until the second week of October.
When is the best time to see a MacGillivray's Warbler in Arizona?
The MacGillivray's Warbler is reported most often in the second week of September, on about 12% of Arizona checklists.
Where in Arizona are MacGillivray's Warblers seen most often?
By county, Apache County, Greenlee County, and Santa Cruz County have the highest peak reporting rates for the MacGillivray's Warbler (counties with at least 200 checklists).