Below, we highlight seasonal intervals for which 50% of migrants historically pass through each city, as measured by radar from 1995 to 2018. Dotted black circles denote weather surveillance radar coverage areas.
Dates below display seasonal intervals for which 50% of migrants historically pass through each city, as measured by radar from 1995 to 2018.
| City | Spring | Fall |
|---|---|---|
| Arvada | May-04 to May-18 | September-01 to September-27 |
| Aurora | May-04 to May-18 | September-01 to September-27 |
| Boulder | May-04 to May-18 | September-01 to September-27 |
| Brighton | May-04 to May-18 | September-01 to September-27 |
| Broomfield | May-04 to May-18 | September-01 to September-27 |
| Castle Rock | May-04 to May-18 | September-01 to September-27 |
| Centennial | May-04 to May-18 | September-01 to September-27 |
| Colorado Springs | May-04 to May-18 | September-06 to September-30 |
| Commerce City | May-04 to May-18 | September-01 to September-27 |
| Dakota Ridge | May-04 to May-18 | September-01 to September-27 |
| Denver | May-04 to May-18 | September-01 to September-27 |
| Englewood | May-04 to May-18 | September-01 to September-27 |
| Fort Collins | May-04 to May-17 | September-01 to September-24 |
| Grand Junction | May-03 to May-23 | August-31 to September-24 |
| Greeley | May-04 to May-18 | September-01 to September-27 |
| Highlands Ranch | May-04 to May-18 | September-01 to September-27 |
| Ken Caryl | May-04 to May-18 | September-01 to September-27 |
| Lakewood | May-04 to May-18 | September-01 to September-27 |
| Littleton | May-04 to May-18 | September-01 to September-27 |
| Longmont | May-04 to May-18 | September-01 to September-27 |
| Loveland | May-04 to May-18 | September-01 to September-27 |
| Northglenn | May-04 to May-18 | September-01 to September-27 |
| Parker | May-04 to May-18 | September-01 to September-27 |
| Pueblo | May-04 to May-18 | September-06 to September-30 |
| Pueblo West | May-04 to May-18 | September-06 to September-30 |
| Security-Widefield | May-04 to May-18 | September-06 to September-30 |
| Thornton | May-04 to May-18 | September-01 to September-27 |
| Westminster | May-04 to May-18 | September-01 to September-27 |
| Wheat Ridge | May-04 to May-18 | September-01 to September-27 |
