The 2025 South Texas International Marathon (STIM) will take place on Sunday, December 7, 2025, in the Mercedes area of South Texas. This third annual event features a point-to-point course that winds through four historic cities—Donna, Weslaco, Mercedes, and La Feria—across two counties, starting at Donna Main Square Park and concluding at Weslaco City Hall. In early December, Mercedes experiences mild winter weather with average temperatures ranging from the mid-50s to low-70s Fahrenheit, with low humidity and minimal precipitation expected. Participants can anticipate a flat, fast USATF-certified course designed for competitive times, comprehensive race support including medical personnel and professional chip timing, and a finish line celebration featuring authentic regional cuisine. The event emphasizes community health and wellness while offering runners the opportunity to qualify for the Boston Marathon.
What distances are available for this event?
→Full Marathon: 26.2 miles (USATF-Certified, Boston Qualifier)
→Half Marathon: 13.1 miles
→6-Person Relay: 26.2 miles split among six runners
What are the registration fees?
→Full Marathon: $110 (regular price; originally $120)
→Half Marathon: $80 (regular price; originally $90)
→6-Person Relay: $330 (regular price; originally $340)
→Note: All prices increase after October 31, 2025, at 11:59 PM CDT
What time do the races start?
→Marathon: 7:00 AM CST
→Half Marathon: 8:00 AM CST
→6-Person Relay: 7:00 AM CST
What is the finish time limit for the marathon?
The marathon has a finish time limit of 6.5 hours, which equates to a 14:50 pace per mile.
What is included in race registration?
→Professional chip timing
→Custom race bib
→Free action photos
→Tech race shirt
→Access to the 3-day STIM Health & Fitness Expo
→Medical support throughout the course
→Transportation from finish line back to start line
→Authentic regional cuisine at finish line (while supplies last)
When is the expo, and what are its hours?
→Friday, December 5, 2025: Expo opens at 5:00 PM with Packet Pick-Up and VIP Mixer (7–9 PM), closes at 9:00 PM
→Saturday, December 6, 2025: Expo continues (times to be announced)
→Sunday, December 7, 2025: Expo continues (times to be announced)
What is the course profile like?
The course is flat and fast, USATF-certified, and designed as a point-to-point route that passes through four historic South Texas cities and two counties, making it ideal for achieving competitive times.
Is this race a Boston Marathon qualifier?
Yes, the full marathon distance (26.2 miles) is a USATF-certified Boston Qualifier event.
What is the overall theme or mission of this event?
The South Texas International Marathon promotes awareness of diabetes and healthy lifestyles within the community. The event was founded by Basilio Mendoza, who was inspired after volunteering at the Boston Marathon in 2019.
What are the overall race day hours?
→Marathon and 6-Person Relay: 7:00 AM – 2:00 PM CST
→Half Marathon: 8:00 AM – 2:00 PM CST
What should I expect regarding weather conditions on race day?
Early December in Mercedes typically features mild winter weather with temperatures ranging from the mid-50s to low-70s Fahrenheit. Conditions are generally characterized by low humidity and minimal precipitation, providing favorable running conditions for distance racing.
❓ Frequently Asked Questions
Q: When is 2025 South Texas International Marathon?
