Days 11-15. 3 waves, each starting at 12:00.
No crises in this tier.
Starts with 
Endless: Grid Collapse.
Each wave pays its kind's pack from Endless rewards, tiers 1-4 when it ends.
Waves
3| Day | Starts | Lasts | Wave | Zombies | Health | Attack | Sends |
|---|---|---|---|---|---|---|---|
| 12 | 12:00 | 8 h | Regular | 22 | ×3 | ×3 | All but Hulk Zombie, Armored Crawler Zombie |
| 14 | 12:00 | 12 h | Regular | 13 | ×3 | ×3 | All but Charger Zombie |
| 15 | 12:00 | 18 h | Final | 36 | ×3 | ×3 | All but Armored Crawler Zombie |
Weather
5Rolled from Endless weather, tiers 2-3.
| Weather | Chance a day | Light | Cold |
|---|---|---|---|
 Clear | 38% | 2 | 0 |
 Cloudy | 29% | 1 | 0 |
 Rainy | 17% | 1 | 0 |
 Mild Cold | 8% | 1 | 1 |
 Continuous Rain | 8% | 0.5 | 0 |
From the game files11
EndlessTier 3
| id | 3 |
|---|---|
| Tier | 3 |
| EnterDay | 11 |
| CalmDays | 1 |
| WaveClockHour | 12 |
| WaveTemplateId | 3 |
| WaveCountMul | 1 |
| WaveHpMul | 1.5 |
| WeatherPoolId | 2 |
| DronePowerMul | 1 |
| PledgeWaveTemplateId | 103 |
| BroadcastEventId | 48002 |
| WaveDayTemplates | [0,1032,0,1034,1035] |
| WaveRewardSetIds | [71053,71054,71055] |
| WaveLootGroupId | 8054 |