The Short Answer
On the Endurance Grid calendar, half marathons run all year, with peaks in fall and spring. October 2026 held 441, the most of any month since May 16, 2026, and the busiest month listed so far for 2027 is April, with 360. Summer is the quiet stretch, and Florida, California, and Texas lead the winter.
Based on 1,640 half marathons held on the Endurance Grid calendar since May 16, 2026, when our race history begins, and 2,859 listed ahead, as of November 8, 2026. We don't list every half marathon in the US.
Races by Month
Our race history begins on May 16, 2026, so the first column covers the months since then. The second column is what race directors have listed with us so far. Listings fill in as races get closer, so the later months will keep rising.
Month | Held in 2026 | Listed so far, Nov 2026 to Oct 2027 |
|---|---|---|
January | — | 320 in 37 states |
February | — | 280 in 34 states |
March | — | 320 in 38 states |
April | — | 360 in 45 states |
May | 127 in 32 states (from May 16) | 272 in 44 states |
June | 188 in 34 states | 159 in 36 states |
July | 205 in 37 states | 138 in 34 states |
August | 260 in 34 states | 102 in 34 states |
September | 330 in 45 states | 128 in 38 states |
October | 441 in 46 states | 104 in 40 states |
November | 89 in 36 states (through Nov 7) | 357 in 39 states (Nov 8 on) |
December | — | 307 in 34 states |
See every upcoming half marathon.
Fall: The Busiest Stretch
Since our history began, half marathons on our calendar climbed every month from June (188) to October (441), the busiest month so far. October also had the widest spread, with half marathons in 46 states.
Spring: The Second Peak
For 2027, the months with the most half marathons listed so far are April (360), January (320), and March (320). April's 360 are spread across 45 states.
Summer: The Quiet Stretch
Summer is the slowest season on our calendar. In 2026, June held 188 half marathons and July 205, less than half of October's 441.
Winter Half Marathons
Unlike triathlons, half marathons keep going through the winter. For December 2026 through February 2027, our calendar lists 147 in Florida, 110 in California, and 109 in Texas so far.
Upcoming Half Marathons
The Next Half Marathons on Our Calendar
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