Best Time to See Black Widows in Illinois
June, October and May is the best time to see black widows in Illinois. Based on 189 verified iNaturalist observations, here is exactly when black widows are most active across the year in Illinois.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated July 22, 2026.
Northern Black Widow · Joseph McPhail CC BY
Western Black Widow · Rebecca Ray CC BY
Western Black Widow · Michael Eisen CC BY
189 verified observations of black widows in Illinois, recorded across 10 months of the year on iNaturalist.
When black widows are recorded in Illinois
Peak month
June
50 records (26.5% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 0 | 0% |
| February | 0 | 0% |
| March | 9 | 4.8% |
| April | 18 | 9.5% |
| Maypeak | 21 | 11.1% |
| Junepeak | 50 | 26.5% |
| July | 15 | 7.9% |
| August | 19 | 10.1% |
| September | 20 | 10.6% |
| Octoberpeak | 31 | 16.4% |
| November | 2 | 1.1% |
| December | 4 | 2.1% |
Black Widows you are most likely to see
| Species | Verified observations |
|---|---|
| Northern Black Widow | 149 |
| Brown Widow | 17 |
| Southern Black Widow | 9 |
Weather to expect, source Open-Meteo
Typical weather in Illinois
Recent typical conditions by month, so you can plan a trip around both when black widows are active and what the weather is doing. The best months to look for black widows sit around 48 to 83 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 38°F | 23°F | 3" |
| Feb | 40°F | 22°F | 3.1" |
| Mar | 53°F | 34°F | 4.8" |
| Apr | 63°F | 43°F | 4.1" |
| Maybest time | 73°F | 54°F | 4.6" |
| Junbest time | 83°F | 64°F | 3.5" |
| Jul | 85°F | 68°F | 4.3" |
| Aug | 83°F | 66°F | 3.9" |
| Sep | 79°F | 61°F | 3" |
| Octbest time | 65°F | 48°F | 4.9" |
| Nov | 52°F | 35°F | 1.8" |
| Dec | 45°F | 29°F | 2.3" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Illinois. Weather varies year to year, so treat these as a guide.
Sightings of black widows in Illinois peak in June, when 50 of the year's 189 verified observations are logged — about 26.5% of the annual total. Activity stays high through June, October and May.
The quietest stretch is January and February, when black widows are hardest to find — no verified records exist for January. If a reliable sighting matters, plan around the peak window rather than the off-season.
The black widows you are most likely to encounter in Illinois are Northern Black Widow, Brown Widow and Southern Black Widow — the most-recorded species in the state. Each keeps its own seasonal rhythm, but the month-by-month pattern above reflects every reported sighting together.
Where to go
Best places to see black widows in Illinois
- Lewis & Clark National Historic Trail — National Historic Trail
- Lincoln Home National Historic Site — National Historic Site
- Emmett Till and Mamie Till-Mobley National Monument — National Monument
- Mormon Pioneer National Historic Trail — National Historic Trail
- New Philadelphia National Historic Site — National Historic Site
- Pullman National Historical Park — National Historical Park
Frequently asked questions
What is the best month to see black widows in Illinois?+
June is the single best month, and the broader peak window runs through June, October and May, based on 189 verified iNaturalist observations.
When are black widows hardest to see in Illinois?+
January is the quietest month for black widows in Illinois, with no verified records on iNaturalist.
Are black widows active year-round in Illinois?+
Black widows are recorded in 10 of 12 months in Illinois, concentrated around June and October.
More wildlife in Illinois