US Races Sept. 19–20, 2026: Air Force Marathon, Top of Utah, Fox Valley, Santa Fe
Quick answer — Race day is tomorrow. The Air Force Marathon goes at Wright-Patterson Saturday with the 5K and 10K at 6:30 a.m. EDT and the marathon and half at 7:15, into 60°F air and a clear sky. Top of Utah starts down the canyon at 7:10 a.m. MDT at 47°F, and the Equinox Marathon climbs Ester Dome out of Fairbanks at 8 in 43°F. Sunday is the wet half: Fox Valley in St. Charles now carries a 71% chance of showers and storms at its 7 a.m. CDT gun. Santa Fe stays dry and sunny at 7:30, the DC Half is sold out, and Brooklyn's Prospect Park half improved to 48%.
What is running Saturday, Sept. 19?
| Race | City | Start (local) | Entry as of Friday | At the gun (NWS, Sept. 18) |
|---|---|---|---|---|
| Air Force Marathon | Dayton, OH (Wright-Patterson AFB) | 5K & 10K 6:30 a.m., half & marathon 7:15 a.m. EDT | Expo only: marathon $145, half $125, 10K $75, 5K $60 | 60°F, dew 56°F, E 5 mph, 1% rain, clear |
| Cytiva Top of Utah Marathon | Logan, UT | Marathon 7:10, half 7:30, 10K 7:50, 5K 8:10 a.m. MDT | Online to 7:00 a.m. race morning. Marathon $130, half $80 | 47°F, dew 47°F, calm, 18% rain |
| 62nd Equinox Marathon & Relay | Fairbanks, AK | 8:00 a.m. AKDT, UAF Athletic Field | Closes 7:59 p.m. tonight. $110 plus fee | 43°F, dew 43°F, calm, 25% showers |
| DC Half 5K | Washington, DC (West Potomac Park) | 8:00 a.m. EDT | Full. $60, no new entries | 64°F, dew 56°F, NE 7 mph, 6% rain |
What is running Sunday, Sept. 20?
| Race | City | Start (local) | Entry as of Friday | At the gun (NWS, Sept. 18) |
|---|---|---|---|---|
| Fox Valley Marathon, half, Fall Final 20 | St. Charles, IL | Marathon, half and 20-mile 7:00 a.m., 5K 7:10 a.m. CDT | Open. No refunds, no transfers, $35 to defer | 63°F, dew 63°F, NE 10 mph, 71% storms |
| Capitol Ford Santa Fe International Half | Santa Fe, NM | Half & 3-Amigos relay 7:30, 5K 8:00, kids 1K 9:00 a.m. MDT | Open. Roads into the start close at 7:00 a.m. | 55°F, dew 46°F, N 5 mph, 0% rain, sunny |
| DC Half | Washington, DC | 7:00 a.m. EDT | Full. $120 was the last price | 67°F, dew 66°F, S 5 mph, 8% rain |
| Prospect Park Half Marathon | Brooklyn, NY | 8:00 a.m. EDT, Center Drive | Open to 5:00 p.m. tonight. $85.80 with fee | 66°F, dew 55°F, SE 9 mph, 48% rain |
What changed in Friday's forecast?
Four things, and three of them are good news.
Fox Valley is the one that got worse. Thursday's run had St. Charles at 47%; Friday's has 71% with showers and thunderstorms listed as likely from before dawn through noon, 63°F over a 63°F dew point, and a northeast wind climbing from 10 to 15 mph by 10 a.m. Saturated air at 63°F with wind and rain is the least forgiving combination on this board, because you can't shed heat by evaporation and you lose it fast when you stop.
Prospect Park nearly halved, 78% to 48%, and the muggy edge came off with it: dew point 55°F instead of 59°F, air temperature holding at 66–67°F right through the 8 a.m. start and the two hours after. Brooklyn is now a merely damp race rather than a wet one.
Dayton lost its afternoon heat. Thursday had 63°F at the gun and a high near 87°F; Friday has 60°F at 7 a.m., 68°F at 10, 75°F at noon and a high near 78°F. A 4:30 marathoner who starts at 7:15 now finishes in the low 70s rather than the low 80s, which is the difference between a hard finish and a survival one.
Logan's rain moved later. The 7:10 a.m. start is down to 18%, but scattered showers and thunderstorms jump to 35% from 9 to 11 a.m. and 52% by noon. Early finishers get the dry morning; anyone still on course after 11 probably does not.
What should you wear at each start?
The spread on this board is 43°F to 67°F, which is three different kit decisions. Our kit-by-temperature chart has the full bands; here is where each start lands.
| Start | Band | What that means |
|---|---|---|
| Equinox, Fairbanks, 43°F | 40–45°F | Tights, long sleeve, gloves and a hat you can stuff in a pocket. The Ester Dome climb runs colder than the valley reading, and 25% showers means a brim helps. |
| Top of Utah, Logan, 47°F | 45–55°F | Shorts or capris with a long sleeve, plus a throwaway layer for the canyon shuttle. You warm 5°F in the first hour and the sun arrives with it. |
| Santa Fe, 55°F, dew 46°F | 50–60°F, dry | Shorts and a short sleeve. Dry air above 6,000 feet means a sunburn and a fluid problem, not a clothing one — the sun is already strong by the 8 a.m. 5K. |
| Air Force Marathon, 60°F | 60°F rising to 78°F | Dress for mile 18, not the corral. Singlet or short sleeve, a cheap top layer you drop at the start line, and a cap for the open stretches of the base. |
| Fox Valley, 63°F in rain | 60°F, saturated, windy | The hardest call here. A thin close-fitting top beats anything absorbent, no cotton anywhere, and dry clothes waiting in the gear bag matter more than what you race in. |
| DC Half, 67°F, dew 66°F | 65°F+, saturated | The least clothing you are comfortable in. Sweat will not evaporate, so pace by effort and take every water stop. |
Runners caught between two sizes in tights for Fairbanks should read the inseam-by-height breakdown our sizing desk published — a tight that ends at the wrong point on the calf is the thing you notice at mile 18 in the cold.
What does the Air Force Marathon cost now?
More than it did yesterday. The $130 marathon window ran through Sept. 17. From today the event is on expo-only pricing: $145 for the marathon, $125 for the half, $75 for the 10K and $60 for the 5K, sold in person at the expo Friday and Saturday. That is a $15 penalty on the long distances and $10 on the short ones for waiting a week. Military registrants keep their discount. The Tailwind Trot kids' 1K runs this evening at 6 p.m.
Four distances leave Wright-Patterson on the same morning, with the two short ones going 45 minutes ahead of the long ones, so a family can split across the field without splitting the day.
What closes tonight?
Two things. Equinox shuts online entry at 7:59 p.m. AKDT tonight, Friday, Sept. 18 — the hardest cutoff on this board. Prospect Park runs to 5:00 p.m. EDT Saturday, so tonight is the comfortable deadline rather than the real one.
The DC Half is gone entirely: Pacers Running has all three West Potomac Park events marked full, the Saturday 5K at $60, the Sunday half at $120 and the two-race District Challenge at $155. Top of Utah is the most forgiving of the lot, with online entry open until 7:00 a.m. race morning and in-person signup at race headquarters Saturday 6 to 7 a.m.
What if you are not racing this weekend?
Then it is a long-run weekend. The weeks-until countdown shows where tomorrow's long run falls for Chicago, Twin Cities, Marine Corps and New York. Six more races run the same two days — Philadelphia, Fox Cities, Sioux Falls, Bismarck, Rochester and Bellingham Bay — and they have their own board on this weekend's second list. If Saturday is your first start ever, the race-morning checklist is a tonight job, not a Saturday-morning one. A 6:30 a.m. 5K in Dayton starts before sunrise, so the low-light gear notes apply to the walk from the car. Last weekend's board is still up in the Sept. 12–13 list, and the wider city-by-city reads land on the daily weather page.
FAQ
What time does the Air Force Marathon start?
The marathon and half marathon start at 7:15 a.m. EDT on Saturday, Sept. 19, 2026, at Wright-Patterson Air Force Base. The 5K and 10K go first, at 6:30 a.m.
Will it rain at the Fox Valley Marathon?
Probably. Friday's National Weather Service hourly forecast for St. Charles gives a 71% chance of showers and thunderstorms at the 7:00 a.m. CDT start, holding at 71% through noon, at 63°F with a matching dew point and a northeast wind of 10 to 15 mph.
Can I still register for the Equinox Marathon?
Until 7:59 p.m. AKDT tonight, Friday, Sept. 18, on the event's RunSignup page. There is no race-morning entry.
TL;DR — Seven races, Sept. 19–20. Saturday: Air Force Marathon 7:15 a.m. EDT at 60°F and clear, now at expo-only pricing of $145; Top of Utah 7:10 a.m. MDT at 47°F with rain arriving mid-morning; Equinox in Fairbanks at 8 in 43°F, entry closing 7:59 tonight. Sunday: Fox Valley 7 a.m. CDT with a 71% storm chance, Santa Fe half 7:30 dry and sunny, Prospect Park 8 a.m. down to 48%, DC Half sold out.
Sources
- Start times, pricing and entry status: each event's own registration page — usafmarathon.com expo-only pricing table, read Sept. 18, 2026; logandowntown.org and RunnerCard for Top of Utah; RunSignup for the Equinox Marathon, the DC Half and the Prospect Park Half; fv26.com for Fox Valley; santafehalfmarathon.com.
- Forecasts: National Weather Service hourly gridpoint forecasts for Wright-Patterson AFB (ILN), Logan (SLC), Fairbanks (AFG), West Potomac Park (LWX), St. Charles (LOT), Santa Fe (ABQ) and Prospect Park (OKX), pulled Friday, Sept. 18, 2026, 7:50 a.m. ET. Thursday and Tuesday values quoted for comparison come from the same grids on those dates.
- Weekend listings cross-checked against marathonguide.com and findarace.com.