CIM vs Houston: Which Is the Better BQ Attempt?

Published September 20, 2026 · Estimates, updated each registration cycle

With the Boston 2027 application window closed, the next realistic qualifying target for most runners is the September 2027 registration for the 2028 race. Two winter marathons dominate that conversation in the United States: the California International Marathon on Sunday, December 6, 2026, and the Chevron Houston Marathon on Sunday, January 17, 2027. Both are excellent. They are good in different ways, and the right pick depends on three things: how your legs handle a rolling descent, how they handle humidity, and how much of a second chance you want to leave yourself.

The short version

Take CIM if you want the deepest field of people running exactly your goal pace, the most reliable cool and dry morning of the two, and your buffer banked six weeks earlier. Take Houston if you run better on a genuinely flat course, want six more weeks of training in your legs, or cannot get a CIM entry because it sold out in the spring.

Course profile

CIM runs point to point from Folsom to the state capitol and loses roughly 340 feet net, but the first half is a sequence of short climbs and drops rather than a smooth ramp. That profile helps a prepared runner and punishes an unprepared one, because the descents load the quads eccentrically for two hours before the flat finish asks for turnover. Houston is close to sea level and honestly flat, a loop out from downtown and back, with no climb worth planning around. Neither race comes anywhere near the 1,500 foot net drop that triggers Boston's time index adjustment, so both count at full clock value on an application.

Weather risk

This is the strongest argument for CIM. An early December morning in the Sacramento valley is usually in the 40s Fahrenheit with little wind, which is about as close to a guarantee as American road racing offers. The two failure modes are rain and a headwind, both of which have shown up in past editions. Houston in mid January typically starts in the upper 40s or low 50s, which is fine, but the local variable is humidity rather than heat. A muggy year costs most runners real time over the last 10 kilometres even when the thermometer looks friendly.

Getting in

CIM has no lottery and sells out, often long before the fall. If you are reading this in September and have not entered, check availability first and treat the answer as the decision. Houston also has no lottery, but it offers a guaranteed entry category for a recent qualifying performance from a marathon, half marathon or 10K, with its own submission deadline, plus an open pool until the race fills. For a fast runner planning late, Houston is usually the easier bib to obtain.

Where each one sits in the window

Both finish after the September 2026 registration closed, so both point at the same target: the application you file in September 2027 for the 2028 Boston Marathon. The difference is the six weeks between them and what those weeks buy. A December qualifier leaves a full spring season plus the following fall for a second attempt. A January qualifier leaves slightly less, though still plenty. If you miss at CIM you can reasonably target a March or April backup. If you miss at Houston, your realistic backup is late spring or fall.

What buffer to run for

Neither race gets you into Boston on its own. The BAA accepts from the fastest buffers down, so the number that matters is how far under your age and gender standard you finish. Our central estimate for the 2027 cutoff is about 5:15 with a realistic upper end near 7:00, and the last two completed cycles cut at 6:51 and 4:34. Those are estimates and historical facts respectively, not a forecast of 2028, which is why a target buffer of five minutes is a thin plan and eight minutes is a comfortable one. Put your age, gender and goal time into the cutoff predictor and read the historical column: it replays the buffer you are planning against every real Boston cutoff since 2014, adjusted for the standards in force each year.

Verdict

If you can get an entry and your training includes downhill work, CIM is the better bet, mostly on weather reliability and field depth. If the descent worries you, if the entry is gone, or if six more weeks of build would change your fitness meaningfully, Houston costs you very little. The full reviews are here: CIM and Houston. For the dates that decide which Boston a finish counts toward, see the qualifying window, and for the buffer reasoning see how much buffer you need.