May is the busiest month on the marathon calendar. With ideal temperatures across the northern hemisphere, hundreds of races pack the weekends: Pittsburgh Marathon, Buffalo Marathon, Vermont City Marathon, Ottawa Marathon, the Great Manchester Run, and dozens more.
Below is the complete What Race To Run directory of May races for the year ahead — 25 total events across 19 US races and 6 international destinations. Click any race for course details, registration links, and race-weekend logistics.
Why Race in May?
May is the busiest month on the marathon calendar. Whether you’re targeting a PR, planning a destination weekend with family, or just looking for a great training tune-up, May delivers options across every distance and terrain.
Marquee May Races
May highlights include Red Stag Rotorua Marathon, Vancouver Int’l Marathon & Half Marathon, Colorado Marathon Races, OC Marathon Running Festival, Colorado Marathon, plus dozens of regional half marathons, 5Ks, trail races, and fun runs across the United States and around the world.
All May Races on WRTR
Every May race in our database, sorted by date. Distance markers in the right column indicate the primary race type — many events also offer companion shorter distances like 5K, 10K, and family fun runs.
| Race | Date | Location | Distance |
|---|---|---|---|
| Red Stag Rotorua Marathon | 2027-05-01 | Rotorua, New Zealand | Road Races |
| Vancouver Int’l Marathon & Half Marathon | 2027-05-02 | Burnaby, Canada | Road Races |
| Colorado Marathon Races | 2027-05-02 | Arvada, US | Road Races |
| Lilac Bloomsday Run | 2027-05-02 | Spokane, US | Road Races |
| OC Marathon Running Festival | 2027-05-02 | Newport Beach, US | Road Races |
| Colorado Marathon | 2027-05-02 | Fort Collins, US | Road Races |
| Colorado Marathon Relay | 2027-05-02 | Fort Collins, US | Road Races |
| Lincoln AllSport Marathon & Half Marathon | 2027-05-02 | Lincoln, US | Road Races |
| Pittsburgh Marathon Races | 2027-05-02 | Pittsburgh, US | Road Races |
| Kirkland Half Marathon and 5K | 2027-05-02 | Kirkland, US | Road Races |
| BMO Vancouver Marathon | 2027-05-02 | Vancouver, Canada | Road Races |
| Great Birmingham Run | 2027-05-02 | Birmingham, United Kingdom | Road Races |
| Cocodona 250 | 2027-05-03 | Black Canyon City, US | Road Races |
| Run Revel White Mountains Marathon & Half (Awaiting 2027 Race Date) | 2027-05-04 | Conway, US | Road Races |
| Mountains 2 Beach Marathon & Half Marathon (Awaiting 2027 Race Date) | 2027-05-05 | Ventura, US | Road Races |
| Yosemite Half Marathon | 2027-05-08 | Bass Lake, US | Road Races |
| OneAmerica 500 Festival Mini-Marathon | 2027-05-08 | Indianapolis, US | Road Races |
| Beat the Bridge 8K Seattle | 2027-05-08 | Seattle, US | Road Races |
| Copenhagen Marathon | 2027-05-09 | Copenhagen, Denmark | Road Races |
| Colfax Marathon | 2027-05-16 | Denver, US | Road Races |
| Colfax Marathon Relay | 2027-05-16 | Denver, US | Road Races |
| Cleveland Marathon | 2027-05-16 | Cleveland, US | Road Races |
| New River 1 Mile, 5K, Half Marathon & Marathon (Awaiting 2027 Race Date) | 2027-05-17 | Todd, US | Road Races |
| PUMA Salzburg Marathon | 2027-05-23 | Salzburg, Austria | Road Races |
| BolderBOULDER 10K | 2027-05-31 | Boulder, US | Road Races |
Planning a May Destination Race?
Many of the May events listed above are part of a full race weekend with expos, shake-out runs, and post-race celebrations. Book accommodation early — popular May races like the marquee marathons fill nearby hotels 4-6 months ahead. Check each event page for registration deadlines, qualifying times (for Boston-qualifier races), and bib transfer policies.
New races added every week — submit a May race to be included.