Race-day weather · Sunday, July 25, 2027

San Francisco Marathon weather.

26 San Francisco Marathon race mornings since 2000, measured hour by hour: temperature, dew point, wind, rain, and what the weather cost runners. The forecast for the 2027 race goes live here on Jul 19, six days out.

109 Typical score
at the start The median race morning since 2000: 57°F air + 52°F dew point at 5:15am, across 26 race mornings at the San Francisco International weather station. Barely a penalty: 0% to 0.5% slower.
Start · 5:15am10957° air · 52° dew point
+2 hours · 7:15am11057° air · 53° dew point
+4 hours · 9:15am11561° air · 54° dew point

The San Francisco Marathon course, mile by mile: the elevation, every climb, and how I’d run each stretch.

Your goal pace on a typical race morning

Built from the median race morning since 2000, averaged across the hours you’d be running. Where the weather costs time, each cell gives the adjusted finish time and the pace per mile to run instead. Six days out, the real forecast replaces it.

Goal on a cool dayStarting 5:15amStarting 5:30am
2:456:18/mi2:45 to 2:466:18–6:19/mi0% to 0.5% slower · score 1102:45 to 2:466:18–6:19/mi0% to 0.5% slower · score 110
3:006:52/mi3:00 to 3:016:52–6:54/mi0% to 0.5% slower · score 1103:00 to 3:016:52–6:54/mi0% to 0.5% slower · score 110
3:157:26/mi3:16 to 3:177:28–7:31/mi0.5% to 1% slower · score 1113:16 to 3:177:28–7:31/mi0.5% to 1% slower · score 111
3:308:01/mi3:31 to 3:328:03–8:05/mi0.5% to 1% slower · score 1113:31 to 3:328:03–8:05/mi0.5% to 1% slower · score 111
3:458:35/mi3:46 to 3:478:37–8:40/mi0.5% to 1% slower · score 1113:46 to 3:478:37–8:40/mi0.5% to 1% slower · score 111
4:009:09/mi4:01 to 4:029:12–9:15/mi0.5% to 1% slower · score 1114:01 to 4:029:12–9:15/mi0.5% to 1% slower · score 111
4:3010:18/mi4:31 to 4:3310:21–10:24/mi0.5% to 1% slower · score 1124:31 to 4:3310:21–10:24/mi0.5% to 1% slower · score 112
5:0011:27/mi5:01 to 5:0311:30–11:33/mi0.5% to 1% slower · score 1125:01 to 5:0311:30–11:33/mi0.5% to 1% slower · score 112
How I’d race a typical year

Start 2 to 3 seconds per mile slower than goal through the first 10 miles. Drink early, because by the time you feel the heat the deficit is already there, and race the last 10K on feel.

Race week, start to finish: how I’d run the three-week taper, what to take in during the race, how much to slow down in heat and humidity, and what the four weeks after should look like.

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San Francisco Marathon weather history: every race morning since 2000

Every row in the table below is a measurement from the San Francisco International weather station, taken nearest 5:15am (today’s first-wave start) and again three hours later. Start times have moved over the years, so treat 5:15am as a clock time, not always the gun. Across 26 race mornings:

  • A typical 5:15am reading is 57°F with a 52°F dew point, a combined score of 109.
  • The warmest was 2014: 62°F with a 58°F dew point at 5:15am, a score of 120.
  • The most humid was 2014, with a 58°F dew point.
  • The coldest was 2013, at 52°F.
  • On 25 of 26 race mornings the 5:15am score was above 100, enough to call for a pace adjustment. Three hours later, 26 of 26 were.
  • The windiest start was 2026: W wind at 15 mph.
  • Rain fell in the first 5 hours on 1 of 26 race mornings (2 more saw only a trace).
San Francisco Marathon weather by year · air / dew point (°F), combined score, wind and rain
YearDateAir / dew at 5:15amScoreAir / dew at 8:15amScoreWind at 5:15amRain
2026Jul 2660° / 56°11661° / 56°117W 15 mphDry
2025Jul 2757° / 55°11258° / 55°113WSW 7 mphTrace
2024Jul 2856° / 52°10857° / 53°110SSW 5 mphDry
2023Jul 2360° / 52°11261° / 53°114WNW 10 mphDry
2022Jul 2454° / 50°10457° / 51°108W 3 mphDry
2021Sep 1961° / 57°11861° / 56°117WNW 7 mphDry
2020–Virtual only (COVID-19), no race morning
2019Jul 2860° / 52°11264° / 53°117W 9 mphDry
2018Jul 2953° / 51°10456° / 51°107WNW 6 mphDry
2017Jul 2357° / 53°11060° / 54°114WNW 9 mphDry
2016Jul 3157° / 52°10959° / 53°112W 3 mphDry
2015Jul 2659° / 55°11462° / 56°118WNW 3 mphDry
2014Jul 2762° / 58°12063° / 58°121WNW 12 mphLight rain
2013Jun 1652° / 47°9954° / 48°102W 9 mphDry
2012Jul 2955° / 50°10555° / 50°105SW 9 mphDry
2011Jul 3159° / 52°11160° / 52°112SW 5 mphDry
2010Jul 2556° / 50°10657° / 50°107W 8 mphDry
2009Jul 2654° / 51°10556° / 52°108W 6 mphDry
2008Aug 355° / 51°10656° / 51°107W 3 mphDry
2007Jul 2957° / 52°10959° / 52°111W 6 mphDry
2006Jul 3059° / 54°11362° / 55°117WNW 3 mphDry
2005Jul 3156° / 53°10957° / 54°111WNW 12 mphDry
2004Aug 159° / 57°11660° / 57°117WSW 7 mphTrace
2003Jul 2756° / 54°11058° / 55°113W 12 mphDry
2002Jul 2861° / 55°11663° / 55°118SW 5 mphDry
2001Jul 856° / 54°11059° / 56°115W 6 mphDry
2000Jul 954° / 51°10557° / 51°108W 7 mphDry

Readings from the San Francisco International ASOS weather station (NOAA/FAA, via the Iowa Environmental Mesonet), the observation nearest each hour. Scores above 100 call for a pace adjustment. Rain is the total the station measured in the 5 hours after 5:15am. Download every hour as a CSV.

How the score works

Add the air temperature to the dew point, both in Fahrenheit. That combined score is closer to what your body feels than the temperature alone, because dew point decides whether your sweat can evaporate, and evaporating sweat is how you shed heat at race pace. The bands below are the same ones my heat pace calculator uses, and that page has the full chart and the physiology behind it.

Combined score → how much to slow down
  • 100 or lessNo pace adjustment
  • 101 – 1100% to 0.5% slower
  • 111 – 1200.5% to 1% slower
  • 121 – 1301% to 2% slower
  • 131 – 1402% to 3% slower
  • 141 – 1503% to 4.5% slower
  • 151 – 1604.5% to 6% slower
  • 161 – 1706% to 8% slower
  • 171 – 1808% to 10% slower
  • Above 180Hard running is not recommended

The bands are a coach's rule of thumb, not a lab measurement. Treat each range as a starting point and let effort make the final call.

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Other race-day weather pages

Twin Cities MarathonSunday, October 4, 202695Race day at the startNo adjustment needed Chicago MarathonSunday, October 11, 2026113Race day at the startSlight penalty: 0.5% to 1% slower Columbus MarathonSunday, October 18, 202664Forecast at the startNo adjustment needed Detroit MarathonSunday, October 18, 202672Forecast at the startNo adjustment needed Marine Corps MarathonSunday, October 25, 202694Typical startNo adjustment needed NYC MarathonSunday, November 1, 202683Typical startNo adjustment needed Philadelphia MarathonSunday, November 22, 202673Typical startNo adjustment needed California International MarathonSunday, December 6, 202683Typical startNo adjustment needed Honolulu MarathonSunday, December 13, 2026136Typical startReal penalty: 2% to 3% slower Houston MarathonSunday, January 17, 202784Typical startNo adjustment needed LA MarathonSunday, March 7, 202799Typical startNo adjustment needed Boston MarathonMonday, April 19, 202784Typical startNo adjustment needed Eugene MarathonSunday, April 25, 202789Typical startNo adjustment needed Flying Pig MarathonSunday, May 2, 2027102Typical startBarely a penalty: 0% to 0.5% slower Pittsburgh MarathonSunday, May 2, 202799Typical startNo adjustment needed Rock 'n' Roll San Diego MarathonSunday, June 6, 2027119Typical startSlight penalty: 0.5% to 1% slower Grandma's MarathonSaturday, June 19, 2027112Typical startSlight penalty: 0.5% to 1% slower

Course guides, mile by mile: Twin Cities Marathon, Chicago Marathon, Columbus Marathon, Detroit Marathon, Marine Corps Marathon, NYC Marathon, Philadelphia Marathon, California International Marathon, Honolulu Marathon, Houston Marathon, LA Marathon, Boston Marathon, Eugene Marathon, Flying Pig Marathon, Pittsburgh Marathon, Rock 'n' Roll San Diego Marathon, Grandma's Marathon. All race-day weather pages.

RunFitCoach is not affiliated with the The San Francisco Marathon or its organizers. Observations from the San Francisco International ASOS station (NOAA/FAA) via the Iowa Environmental Mesonet. Data updated Saturday, October 17, 2026.

Heat is one variable. I plan for all of them.

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