Race-day weather · Sunday, December 6, 2026

California International Marathon weather.

25 California International Marathon race mornings since 2000, measured hour by hour: temperature, dew point, and what the weather cost runners. The forecast for the 2026 race goes live here on Nov 30, six days out.

83 Typical score
at the start The median race morning since 2000: 43°F air + 40°F dew point at 7am, across 25 race mornings at the Sacramento Executive weather station. No adjustment needed.

Start · 7am8343° air · 40° dew point

+2 hours · 9am8845° air · 43° dew point

+4 hours · 11am9653° air · 43° dew point

Your goal time on a typical race morning

Built from the median race morning since 2000, averaged across the hours you’d be running. Six days out, the real forecast replaces it.

Goal on a cool day	Adjusted finish
2:45	No changescore 86
3:00	No changescore 87
3:15	No changescore 88
3:30	No changescore 88
3:45	No changescore 88
4:00	No changescore 89
4:30	No changescore 90
5:00	No changescore 90

How I’d race a typical year

Race the plan as written. This is the weather marathons are built for, and the only real risk is going out too fast because the first miles feel free. Hold goal pace through halfway and let the second half decide itself.

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California International Marathon weather on race morning since 2000

Every row in the table below is a measurement from the Sacramento Executive weather station, taken nearest 7am (today’s first-wave start) and again three hours later. Start times have moved over the years, so treat 7am as a clock time, not always the gun. Across 25 race mornings:

A typical 7am reading is 43°F with a 40°F dew point, a combined score of 83.
The warmest was 2012: 59°F with a 55°F dew point at 7am, a score of 114.
The most humid was 2012, with a 55°F dew point.
The coldest was 2013, at 29°F.
On 4 of 25 race mornings the 7am score was above 100, enough to call for a pace adjustment. Three hours later, 6 of 25 were.

California International Marathon race mornings · air / dew point (°F) and combined score

Year	Date	Air / dew at 7am	Score	Air / dew at 10am	Score
2025	Dec 7	44° / 42°	86	45° / 43°	88
2024	Dec 8	40° / 39°	79	49° / 46°	95
2023	Dec 3	52° / 48°	100	60° / 51°	111
2022	Dec 4	44° / 43°	87	52° / 48°	100
2021	Dec 5	47° / 47°	94	49° / 48°	97
2020	–	Cancelled (COVID-19)
2019	Dec 8	54° / 52°	106	56° / 54°	110
2018	Dec 2	36° / 35°	71	47° / 42°	89
2017	Dec 3	43° / 40°	83	52° / 40°	92
2016	Dec 4	35° / 35°	70	50° / 46°	96
2015	Dec 6	52° / 44°	96	56° / 43°	99
2014	Dec 7	52° / 52°	104	54° / 54°	107
2013	Dec 8	29° / 23°	52	34° / 24°	58
2012	Dec 2	59° / 55°	114	55° / 53°	108
2011	Dec 4	32° / 25°	57	47° / 27°	74
2010	Dec 5	48° / 46°	95	54° / 52°	105
2009	Dec 6	30° / 22°	52	43° / 24°	67
2008	Dec 7	42° / 39°	81	42° / 40°	82
2007	Dec 2	43° / 28°	71	52° / 26°	78
2006	Dec 3	32° / 30°	62	50° / 37°	87
2005	Dec 4	32° / 29°	61	45° / 32°	77
2004	Dec 5	35° / 32°	67	44° / 34°	78
2003	Dec 7	53° / 49°	102	56° / 50°	106
2002	Dec 8	41° / 39°	80	49° / 42°	91
2001	Dec 2	50° / 47°	97	51° / 49°	100
2000	Dec 3	43° / 43°	86	44° / 44°	88

Readings from the Sacramento Executive ASOS weather station (NOAA/FAA, via the Iowa Environmental Mesonet), the observation nearest each hour. Scores above 100 call for a pace adjustment. 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.

Want the next one built around you?

A forecast adjusts a pace. It doesn't know your training, how you handle heat, or how your last long run went. I write every plan by hand and set race-week pacing with each athlete. It starts with a free 20-minute call.

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Other race-day weather pages

NYC MarathonSunday, November 1, 202683Typical startNo adjustment needed Chicago MarathonSunday, October 11, 2026113Race day at the startSlight penalty: 0.5% to 1% slower Boston MarathonMonday, April 19, 202784Typical startNo adjustment needed Philadelphia MarathonSunday, November 22, 202673Typical startNo adjustment needed

All race-day weather pages

RunFitCoach is not affiliated with the California International Marathon or its organizers. Observations from the Sacramento Executive ASOS station (NOAA/FAA) via the Iowa Environmental Mesonet. Data updated Tuesday, October 13, 2026.

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