| December 1, 2018 | Sat | Five Flags Speedway | P | FL | PLM | Snowflake 100 | 100 | PPD to 12/9 |
| December 1, 2018 | Sat | The Dome at America's Center | D/I | MO | Dirt Late Models | Gateway Dirt Nationals | | Bobby Pierce |
| December 1, 2018 | Sat | The Dome at America's Center | D/I | MO | Dirt Modifieds | Gateway Dirt Nationals | | Mike Harrison |
| December 1, 2018 | Sat | The Dome at America's Center | D/I | MO | Midgets | Gateway Dirt Nationals | | Christopher Bell |
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| December 2, 2018 | Sun | Five Flags Speedway | P | FL | SLM | 51st Snowball Derby | 300 | Noah Gragson |
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| December 8, 2018 | Sat | 417 Southern Speedway | P | FL | Southern Spirnt Car Shootout | | | Joey Aguilar |
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| December 9, 2018 | Sun | Five Flags Speedway | P | FL | PLM | Snowflake 100 | 100 | Chase Purdy |
| December 9, 2018 | Sun | Five Flags Speedway | P | FL | Pro Trucks | Snowball 50 | 50 | Josh Hicks |
| December 9, 2018 | Sun | Five Flags Speedway | P | FL | Modifieds of Mayhem | Season Finale | 75 | Augie Grill |
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| December 13, 2018 | Thu | CURE Insurance Arena | D/I | NJ | Micro-Sprints | East Coast Indoor Dirt Nationals Qualifying | | Various |
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| December 14, 2018 | Fri | CURE Insurance Arena | D/I | NJ | Micro-Sprints | East Coast Indoor Dirt Nationals Qualifying | | Various |
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| December 15, 2018 | Sat | CURE Insurance Arena | | NJ | Micro-Sprints | East Coast Indoor Dirt Nationals | | Erick Rudolph |
| December 15, 2018 | Sat | Southern Illinois Center | D/I | IL | USAC National Midgets | Junior Knepper 55 | | Thomas Meseraull |
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| December 28, 2018 | Fri | War Memorial Coliseum | D/I | IN | Midgets | Rumble in Fort Wayne XX1 | | |
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| December 29, 2018 | Sat | War Memorial Coliseum | D/I | IN | Midgets | Rumble in Fort Wayne XX1 | | |
